Benzimidazole derivative and use thereof

ABSTRACT

The present invention aims to provide a compound capable of inhibiting PCA-1 that can be a target for a novel treatment method of various diseases, and pharmaceutical use of the compound. A compound represented by the formula (I): 
                         
wherein each symbol is as defined in the DESCRIPTION, or a pharmaceutically acceptable salt thereof.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is the U.S. national phase of InternationalPatent Application No. PCT/JP2013/055752, filed Mar. 1, 2013, whichclaims the benefit of Japanese Patent Application No. 2012-045267, filedMar. 1, 2012.

TECHNICAL FIELD

The present invention relates to a novel benzimidazole derivative anduse thereof. More particularly, the present invention relates to a novelbenzimidazole derivative having a Prostate Cancer Antigen-1 (PCA-1)inhibitory activity and a PCA-1 inhibitor, a medicament and the likecontaining the compound.

BACKGROUND ART

Prostate cancer, which occupies the number one in the morbidity rate andmortality in Europe and the United States, also shows a rapid increasein the morbidity rate also in Japan due to the westernization of theeating habits. The early-stage cancer of prostate cancer can becompletely cured by operative treatment and the like, and elderlycitizens with prostate cancer or progressive cancer, for whom anoperative treatment is difficult, undergo a hormone therapy. During suchtreatment, however, hormone therapy resistant prostate cancer emerges,and therefore, an effective treatment method of prostate cancer has notbeen currently established as the situation stands.

On the other hand, pancreatic cancer is held to be one of the cancersmost difficult to treat at present. In pancreatic cancer, even when thetumor is removed by surgery, about 90% of them have a relapse and die.For topical progressive irremovable pancreatic cancer, multiple drugcombination therapy mainly using gemcitabine hydrochloride and 5-FU andthe like are applied, and when distant metastasis is found, a multipledrug combination therapy mainly using gemcitabine hydrochloride, and thelike are applied. Nevertheless, the prognosis is 4-6 months in a medianvalue.

Lung cancer is the top in the number of those died of cancer in Japan.Particularly, the number of patients of non-small cell lung cancer isthe highest in the lung cancer. As a therapeutic drug therefor,chemotherapeutic agents such as taxane group and the like have beenused; however, only about 30% regression is observed. As a moleculartarget drug, gefitinib is applicable to patients having mutated EGFR

Therefore, the development of an effective therapeutic drug for thesetypes of cancer is desired, and the foundation for drug discovery needsto be established early.

A novel gene (Prostate Cancer Antigen-1: PCA-1) has been reported, whichhighly expresses in prostate cancer, and does not show high expressionin normal prostate epithelial cell and benign prostatic hyperplasiawhich is a benign tumor (non-patent document 1, non-patent document 2).There have been reported a method using the expression state of PCA-1for the diagnosis of prostate cancer (patent document 1), and anapoptosis promoter, a cell proliferation inhibitor, an agent for theprophylaxis or treatment of cancer and the like, which contain, as anactive ingredient, a compound that suppresses the expression or functionof PCA-1 (patent document 2). PCA-1 is also highly expressed inpancreatic cancer (patent document 3) and non-small cell lung cancer(non-patent document 3). When the PCA-1 expression in these cancer cellswas suppressed using siRNA, a remarkable suppressive action on thegrowth of prostate cancer cell (patent document 2), pancreatic cancercell (patent document 3), and non-small cell lung cancer was observed(non-patent document 3). In addition, a tumor formed by transplantingcancer cells to a mouse showed regression by the administration of siRNAto PCA-1. These results suggest that PCA-1 can be a new molecular targetin the cancer treatment for prostate cancer, pancreatic cancer and thelike.

Moreover, since tRNA demethylated by PCA-1 increases the proteintranslation efficiency, PCA-1 is also useful for the diseases (e.g.,brain neurodegenerative disease, arteriosclerosis) possibly caused by anabnormal protein.

On the other hand, a benzimidazole derivative having the followingstructure has been reported (patent documents 4, 5); however, its actionon the enzyme activity of PCA-1 is not known.

DOCUMENT LIST Patent Documents

-   patent document 1: WO2006/098464-   patent document 2: WO2007/015587-   patent document 3: JP-A-2011-1286-   patent document 4: U.S. Pat. No. 2,895,955-   patent document 5: GB-B-813866

Non-Patent Documents

-   non-patent document 1: The 123rd Annual Meeting of the    Pharmaceutical society of Japan, Abstracts 4, p. 15, 2003-   non-patent document 2: Konishi N et al., Clin Cancer Res. 2005 Jul.    15; 11(14): 5090-7.-   non-patent document 3: Tasaki M et al., Br J Cancer. 2011 104(4):    700-6.

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

The present invention aims to provide a compound effective for a cancerfor which an effective treatment method has not been established and/orwhich shows poor prognosis, such as cancer, particularly prostatecancer, pancreatic cancer and non-small cell lung cancer, and ananti-cancer agent and the like containing said compound as an activeingredient. Furthermore, the present invention aims to provide acompound capable of inhibiting PCA-1, which can be a target for a noveltreatment method for various diseases, and pharmaceutical use of saidcompound.

Means of Solving the Problems

The present inventors have conducted intensive studies in view of theabove-mentioned problem. To be specific, they took note of PCA-1suggested to be a new molecular target in the cancer treatment of, forexample, prostate cancer, pancreatic cancer and the like. Using ascreening system that measures the enzyme activity that demethylatesmethylated cytosine possessed by PCA-1, they have searched for asubstance that inhibits the enzyme activity. As a result, they haveobtained a compound that inhibits the enzyme activity of PCA-1, andfurther suppresses the growth of prostate cancer cells and pancreaticcancer cells in vitro. Using the compound as a seed compound, they haveconducted further studies of the structure-activity correlation andsucceeded in the creation of a series of advantageous compounds, whichresulted in the completion of the present invention.

Accordingly, the present invention provides the following.

-   [1] A compound represented by the formula (I):

-   wherein R₁ is a hydrogen atom or a substituent; R₂ is a substituent;    R₃ is a hydrogen atom or a substituent; and R₄ is a hydrogen atom or    a substituent;-   provided that when R₁ is a hydrogen atom, then R₃ is not methyl; and    when R₁ is a substituent, then R₃ is not a hydrogen atom,-   or a pharmaceutically acceptable salt thereof.-   [2] The compound of the above-mentioned [1], wherein R₁ is-   a hydrogen atom;-   an optionally substituted C₁₋₆ alkyl group;-   an optionally substituted C₆₋₁₀ aryl group; or-   a halogen atom,-   or a pharmaceutically acceptable salt thereof.-   [3] The compound of the above-mentioned [1], wherein R₁ is-   a hydrogen atom;-   a C₁₋₆ alkyl group optionally substituted by a halogen atom;-   a C₆₋₁₀ aryl group optionally substituted by one or more    substituents selected from the group consisting of a halogen atom    and a C₁₋₆ alkyl group; or-   a halogen atom,-   or a pharmaceutically acceptable salt thereof.-   [4] The compound of the above-mentioned [1], wherein R₂ is-   an optionally substituted C₁₋₆ alkyl group; or-   an optionally substituted C₆₋₁₀ aryl group,-   or a pharmaceutically acceptable salt thereof.-   [5] The compound of the above-mentioned [1], wherein R₂ is-   a C₁₋₆ alkyl group or a C₆₋₁₀ aryl group,-   or a pharmaceutically acceptable salt thereof.-   [6] The compound of the above-mentioned [1], wherein R₃ is-   a hydrogen atom;-   an optionally substituted C₇₋₁₁ aralkyl group;-   an optionally substituted C₆₋₁₀ aryl group; or-   an optionally substituted C₁₋₆ alkyl group,-   or a pharmaceutically acceptable salt thereof.-   [7] The compound of the above-mentioned [1], wherein R₃ is a    hydrogen atom;-   a C₇₋₁₁ aralkyl group optionally substituted by one or more    substituents selected from the group consisting of a halogen atom, a    C₁₋₆ alkyl group optionally substituted by a halogen atom, a C₆₋₁₀    aryl group and a C₁₋₆ alkoxy group;-   a C₆₋₁₀ aryl group; or-   a C₁₋₆ alkyl group optionally substituted by one or more    substituents selected from the group consisting of a C₆₋₁₀ aryl    group, a C₁₋₆ alkoxy-carbonyl group, a carboxyl group and a C₃₋₆    cycloalkyl group,-   or a pharmaceutically acceptable salt thereof.-   [8] The compound of the above-mentioned [1], wherein R₄ is-   a hydrogen atom; or-   an optionally substituted C₁₋₆ alkyl group,-   or a pharmaceutically acceptable salt thereof.-   [9] The compound of the above-mentioned [1], wherein R₄ is a    hydrogen atom, or a pharmaceutically acceptable salt thereof.-   [10] The compound of the above-mentioned [1], wherein R₁ is-   a hydrogen atom;-   a C₁₋₆ alkyl group optionally substituted by a halogen atom;-   a C₆₋₁₀ aryl group optionally substituted by one or more    substituents selected from the group consisting of a halogen atom    and a C₁₋₆ alkyl group; or-   a halogen atom,    -   R₂ is-   a C₁₋₆ alkyl group or a C₆₋₁₀ aryl group,    -   R₃ is-   a hydrogen atom;-   a C₇₋₁₁ aralkyl group optionally substituted by one or more    substituents selected from the group consisting of a halogen atom, a    C₁₋₆ alkyl group optionally substituted by a halogen atom, a C₆₋₁₀    aryl group and a C₁₋₆ alkoxy group;-   a C₆₋₁₀ aryl group; or-   a C₁₋₆ alkyl group optionally substituted by one or more    substituents selected from the group consisting of a C₆₋₁₀ aryl    group, a C₁₋₆ alkoxy-carbonyl group, a carboxyl group and a C₃₋₆    cycloalkyl group, and    -   R₄ is a hydrogen atom,-   or a pharmaceutically acceptable salt thereof.-   [11] A compound represented by the following formula:

-   or a pharmaceutically acceptable salt thereof.-   [12] A PCA-1 inhibitor comprising a compound represented by the    formula (I):

-   wherein R₁ is a hydrogen atom or a substituent; R₂ is a substituent;    R₃ is a hydrogen atom or a substituent; and R₄ is a hydrogen atom or    a substituent, or a pharmaceutically acceptable salt thereof.-   [13] The inhibitor of the above-mentioned [12], wherein R₁ is a    hydrogen atom;-   a C₁₋₆ alkyl group optionally substituted by a halogen atom;-   a C₆₋₁₀ aryl group optionally substituted by one or more    substituents selected from the group consisting of a halogen atom    and a C₁₋₆ alkyl group; or-   a halogen atom,    -   R₂ is-   a C₁₋₆ alkyl group or a C₆₋₁₀ aryl group,    -   R₃ is-   a hydrogen atom;-   a C₇₋₁₁ aralkyl group optionally substituted by one or more    substituents selected from the group consisting of a halogen atom, a    C₁₋₆ alkyl group optionally substituted by a halogen atom, a C₆₋₁₀    aryl group and a C₁₋₆ alkoxy group;-   a C₆₋₁₀ aryl group; or-   a C₁₋₆ alkyl group optionally substituted by one or more    substituents selected from the group consisting of a C₆₋₁₀ aryl    group, a C₁₋₆ alkoxy-carbonyl group, a carboxyl group and a C₃₋₆    cycloalkyl group, and    -   R₄ is a hydrogen atom.-   [14] A PCA-1 inhibitor comprising a compound represented by the    following formula:

-   or a pharmaceutically acceptable salt thereof.-   [15] A prophylactic and/or therapeutic drug for a disease involving    PCA-1, comprising a compound represented by the formula (I):

-   wherein R₁ is a hydrogen atom or a substituent; R₂ is a substituent;    R₃ is a hydrogen atom or a substituent; and R₄ is a hydrogen atom or    a substituent, or a pharmaceutically acceptable salt thereof, as an    active ingredient.-   [16] The prophylactic and/or therapeutic drug of the above-mentioned    [15], wherein R₁ is-   a hydrogen atom;-   a C₁₋₆ alkyl group optionally substituted by a halogen atom;-   a C₆₋₁₀ aryl group optionally substituted by one or more    substituents selected from the group consisting of a halogen atom    and a C₁₋₆ alkyl group; or-   a halogen atom,    -   R₂ is-   a C₁₋₆ alkyl group or a C₆₋₁₀ aryl group,    -   R₃ is-   a hydrogen atom;-   a C₇₋₁₁ aralkyl group optionally substituted by one or more    substituents selected from the group consisting of a halogen atom, a    C₁₋₆ alkyl group optionally substituted by a halogen atom, a C₆₋₁₀    aryl group and a C₁₋₆ alkoxy group;-   a C₆₋₁₀ aryl group; or-   a C₁₋₆ alkyl group optionally substituted by one or more    substituents selected from the group consisting of a C₆₋₁₀ aryl    group, a C₁₋₆ alkoxy-carbonyl group, a carboxyl group and a C₃₋₆    cycloalkyl group, and    -   R₄ is a hydrogen atom.-   [17] A prophylactic and/or therapeutic drug for a disease involving    PCA-1, comprising a compound represented by the following formula:

-   or a pharmaceutically acceptable salt thereof.-   [18] The prophylactic and/or therapeutic drug of the above-mentioned    [17], wherein the disease involving PCA-1 is selected from the group    consisting of cancer, a brain neurodegenerative disease and    arteriosclerosis.-   [19] The prophylactic and/or therapeutic drug of the above-mentioned    [18], wherein the cancer is at least one kind selected from the    group consisting of prostate cancer, pancreatic cancer and non-small    cell lung cancer, which has an anticancer action against the    above-mentioned cancers.-   [20] A method for the prophylaxis and/or treatment of a disease    involving PCA-1, comprising administering an effective amount of a    compound represented by the formula (I):

-   wherein R₁ is a hydrogen atom or a substituent; R₂ is a substituent;    R₃ is a hydrogen atom or a substituent; and R₄ is a hydrogen atom or    a substituent, or a pharmaceutically acceptable salt thereof, to a    mammal.-   [21] The method for the prophylaxis and/or treatment of the    above-mentioned [20], wherein R₁ is-   a hydrogen atom;-   a C₁₋₆ alkyl group optionally substituted by a halogen atom;-   a C₆₋₁₀ aryl group optionally substituted by one or more    substituents selected from the group consisting of a halogen atom    and a C₁₋₆ alkyl group; or-   a halogen atom,    -   R₂ is-   a C₁₋₆ alkyl group or a C₆₋₁₀ aryl group,    -   R₃ is-   a hydrogen atom;-   a C₇₋₁₁ aralkyl group optionally substituted by one or more    substituents selected from the group consisting of a halogen atom, a    C₁₋₆ alkyl group optionally substituted by a halogen atom, a C₆₋₁₀    aryl group and a C₁₋₆ alkoxy group;-   a C₆₋₁₀ aryl group; or-   a C₁₋₆ alkyl group optionally substituted by one or more    substituents selected from the group consisting of a C₆₋₁₀ aryl    group, a C₁₋₆ alkoxy-carbonyl group, a carboxyl group and a C₃₋₆    cycloalkyl group, and    -   R₄ is a hydrogen atom.-   [22] A method for the prophylaxis and/or treatment of a disease    involving PCA-1, comprising administering an effective amount of a    compound represented by the following formula:

-   or a pharmaceutically acceptable salt thereof, to a mammal.-   [23] The method for the prophylaxis and/or treatment of the    above-mentioned [22], wherein the disease involving PCA-1 is    selected from the group consisting of cancer, a brain    neurodegenerative disease and arteriosclerosis.-   [24] The method for the prophylaxis and/or treatment of the    above-mentioned [23], wherein the cancer is at least one kind    selected from the group consisting of prostate cancer, pancreatic    cancer and non-small cell lung cancer, which has an anticancer    action against the above-mentioned cancers.-   [25] The compound of any of the above-mentioned [1]-[11] or a    pharmaceutically acceptable salt thereof for the prophylaxis or    treatment of a disease involving PCA-1.-   [26] The compound of the above-mentioned [25], wherein the disease    involving PCA-1 is selected from the group consisting of cancer, a    brain neurodegenerative disease and arteriosclerosis, or a    pharmaceutically acceptable salt thereof.-   [27] The compound of the above-mentioned [26], wherein the cancer is    at least one kind selected from the group consisting of prostate    cancer, pancreatic cancer and non-small cell lung cancer, which has    an anticancer action against the above-mentioned cancers, or a    pharmaceutically acceptable salt thereof.

In the following, a compound represented by the formula (I) (also to bereferred to as compound (I)) and a pharmaceutically acceptable saltthereof are comprehensively referred to as the compound of the presentinvention.

Effect of the Invention

Since the compound of the present invention has a superior inhibitoryaction on the enzyme activity of PCA-1, it is useful for the prophylaxisand/or treatment of a disease involving PCA-1. Particularly, thecompound of the present invention is useful as an anti-cancer agent forprostate cancer, pancreatic cancer, non-small cell lung cancer and thelike. Moreover, it suppresses the growth of prostate cancer cell,pancreatic cancer cell, and non-small cell lung cancer cell in vitro.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing an antitumor action of the compound of thepresent invention (Example 1) in a DU145 cell xenograft model.

DESCRIPTION OF EMBODIMENTS

The present invention is explained in the following. Unless particularlyindicated, the terms used in the present specification have the meaningsgenerally used in the field.

The terms used in the present specification are defined as follows.

Examples of the “halogen atom” include a fluorine atom, a chlorine atom,a bromine atom and an iodine atom.

The “C₁₋₆ alkyl group” means a straight chain or branched alkyl grouphaving 1-6 carbon atoms, and specific examples thereof include methyl,ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl,n-pentyl, isopentyl, tert-pentyl, neopentyl, 2-pentyl, 3-pentyl,n-hexyl, 2-hexyl and the like.

The “C₃₋₆ cycloalkyl group” means a cyclic alkyl group having 3-6 carbonatoms, and specific examples thereof include cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl and the like.

The “C₆₋₁₀ aryl group” means an aryl group having 6-10 carbon atoms, andspecific examples thereof include phenyl, naphthyl and the like.

The “C₇₋₁₁ aralkyl group” means an arylalkyl group having 7-11 carbonatoms (an alkyl group substituted by an aryl group), and specificexamples thereof include a benzyl group, a phenylethyl group, aphenylpropyl group, a naphthylmethyl group and the like.

The “C₁₋₆ alkoxy group” means a straight chain or branched alkoxy grouphaving 1-6 carbon atoms, and specific examples thereof include methoxy,ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy,tert-butoxy, n-pentyloxy, isopentyloxy, tert-pentyloxy, neopentyloxy,2-pentyloxy, 3-pentyloxy, n-hexyloxy, 2-hexyloxy and the like.

The “C₁₋₆ alkoxy group-carbonyl group” means a carbonyl groupsubstituted by a C₁₋₆ alkoxy group (mentioned above), and specificexamples thereof include methoxycarbonyl, ethoxycarbonyl,propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, isobutoxycarbonyl,tert-butoxycarbonyl and the like.

As the substituent that the “C₁₋₆ alkyl group”, “C₆₋₁₀ aryl group” and“C₇₋₁₁ aralkyl group” optionally have, a substituent selected from thegroup consisting of

-   (1) a halogen atom (e.g., fluorine, chlorine, bromine, iodine;    preferably fluorine),-   (2) a lower alkyl group (e.g., a C₁₋₆ alkyl group such as methyl,    ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl,    pentyl, hexyl, and the like, and the like),-   (3) a cycloalkyl group (e.g., a C₃₋₆ cycloalkyl group such as    cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and the like, and    the like),-   (4) a lower alkynyl group (e.g., a C₂₋₆ alkynyl group such as    ethynyl, 1-propynyl, propargyl, and the like, and the like),-   (5) a lower alkenyl group (e.g., a C₂₋₆ alkenyl group such as vinyl,    allyl, isopropenyl, butenyl, isobutenyl, and the like, and the    like),-   (6) an aralkyl group (e.g., a C₇₋₁₂ aralkyl group such as benzyl,    α-methylbenzyl, phenethyl, and the like, and the like),-   (7) an aryl group (e.g., a C₆₋₁₀ aryl group such as phenyl,    naphthyl, and the like, and the like, preferably a phenyl group),-   (8) a lower alkoxy group (e.g., a C₁₋₆ alkoxy group such as methoxy,    ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy,    tert-butoxy, and the like, and the like),-   (9) an aryloxy group (e.g., a C₆₋₁₀ aryloxy group such as phenoxy,    and the like, and the like),-   (10) a formyl group or a lower alkanoyl group (e.g., a C₁₋₆    alkyl-carbonyl group such as acetyl, propionyl, butyryl, isobutyryl,    and the like, and the like),-   (11) an arylcarbonyl group (e.g., a C₆₋₁₀ aryl-carbonyl group such    as benzoyl, naphthoyl, and the like, and the like),-   (12) a formyloxy group or a lower alkanoyloxy group (e.g., a C₁₋₆    alkyl-carbonyloxy group such as acetyloxy, propionyloxy, butyryloxy,    isobutyryloxy, and the like, and the like),-   (13) an arylcarbonyloxy group (e.g., a C₆₋₁₀ aryl-carbonyloxy group    such as benzoyloxy, naphthoyloxy, and the like, and the like),-   (14) a carboxyl group,-   (15) a lower alkoxycarbonyl group (e.g., a C₁₋₆ alkoxy-carbonyl    group such as methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl,    isopropoxycarbonyl, butoxycarbonyl, isobutoxycarbonyl,    tert-butoxycarbonyl, and the like, and the like),-   (16) an aralkyloxycarbonyl group (e.g., a C₇₋₁₂ aralkyloxycarbonyl    group such as benzyloxycarbonyl, and the like, and the like),-   (17) a carbamoyl group,-   (18) a mono-, di- or tri-halogeno-lower alkyl group (e.g., a mono-,    di- or tri-halogeno-C₁₋₆ alkyl group such as chloromethyl,    dichloromethyl, trifluoromethyl, 2,2,2-trifluoroethyl, and the like,    and the like),-   (19) an oxo group,-   (20) an amidino group,-   (21) an imino group,-   (22) an amino group,-   (23) a mono-lower alkylamino group (e.g., a mono-C₁₋₆ alkylamino    group such as methylamino, ethylamino, propylamino, isopropylamino,    butylamino, and the like, and the like),-   (24) a di-lower alkylamino group (e.g., a di-C₁₋₆ alkylamino group    such as dimethylamino, diethylamino, dipropylamino,    diisopropylamino, dibutylamino, N-ethyl-N-methylamino, and the like,    and the like),-   (25) a 3- to 8-membered nitrogen-containing heterocyclic group    optionally having substituent(s) and optionally containing, besides    carbon atom and one nitrogen atom, 1-3 hetero atoms selected from a    nitrogen atom, an oxygen atom and a sulfur atom (e.g., a 3- to    8-membered nitrogen-containing heterocyclic group optionally having    1-5 substituents selected from a halogen atom, a nitro group, a    cyano group, a hydroxy group, an optionally halogenated C₁₋₆ alkyl    group, an optionally hal ,ogenated C₁₋₆ alkoxy group, an amino    group, a mono-C₁₋₆ alkylamino group, a di-C₁₋₆ alkylamino group, a    carboxyl group, a C₁₋₆ alkyl-carbonyl group, a C₁₋₆ alkoxy-carbonyl    group, a carbamoyl group, a mono-C₁₋₆ alkyl-carbamoyl group, a    di-C₁₋₆ alkyl-carbamoyl group, a C₆₋₁₀ aryl-carbamoyl group, a C₆₋₁₀    aryl group, a C₆₋₁₀ aryloxy group, and an optionally halogenated    C₁₋₆ alkyl-carbonylamino group, an oxo group and the like, and    optionally containing, besides carbon atom and one nitrogen atom,    1-3 hetero atoms selected from a nitrogen atom, an oxygen atom and a    sulfur atom; for example, aziridinyl, azetidinyl, pyrrolidinyl,    pyridyl, pyrrolinyl, pyrrolyl, imidazolyl, pyrazolyl,    imidazolidinyl, piperidyl, oxadiazolyl, isoxazolyl, morpholinyl,    dihydropyridyl, tetrahydropyridyl, piperazinyl, N-methylpiperazinyl,    N-ethylpiperazinyl and the like),-   (26) an alkylenedioxy group (e.g., a C₁₋₃ alkylenedioxy group such    as methylenedioxy, ethylenedioxy, and the like, and the like),-   (27) a hydroxy group,-   (28) a nitro group,-   (29) a cyano group,-   (30) a mercapto group,-   (31) a sulfo group,-   (32) a sulfino group,-   (33) a phosphono group,-   (34) a sulfamoyl group,-   (35) a mono-lower alkylsulfamoyl group (e.g., a mono-C₁₋₆    alkylsulfamoyl group such as N-methylsulfamoyl, N-ethylsulfamoyl,    N-propylsulfamoyl, N-isopropylsulfamoyl, N-butylsulfamoyl, and the    like, and the like),-   (36) a di-lower alkylsulfamoyl group (e.g., a di-C₁₋₆ alkylsulfamoyl    group such as N,N-dimethylsulfamoyl, N,N-diethylsulfamoyl,    N,N-dipropylsulfamoyl, N,N-dibutylsulfamoyl, and the like, and the    like),-   (37) a lower alkylthio group (e.g., a C₁₋₆ alkylthio group such as    methylthio, ethylthio, propylthio, isopropylthio, butylthio,    sec-butylthio, tert-butylthio, and the like, and the like),-   (38) an arylthio group (e.g., a C₆₋₁₀ arylthio group such as    phenylthio, naphthylthio, and the like, and the like),-   (39) a lower alkylsulfinyl group (e.g., a C₁₋₆ alkylsulfinyl group    such as methylsulfinyl, ethylsulfinyl, propylsulfinyl,    butylsulfinyl, and the like, and the like),-   (40) an arylsulfinyl group (e.g., a C₆₋₁₀ arylsulfinyl group such as    phenylsulfinyl, naphthylsulfinyl, and the like, and the like),-   (41) a lower alkylsulfonyl group (e.g., a C₁₋₆ alkylsulfonyl group    such as methylsulfonyl, ethylsulfonyl, propylsulfonyl,    butylsulfonyl, and the like, and the like),-   (42) an arylsulfonyl group (e.g., a C₆₋₁₀ arylsulfonyl group such as    phenylsulfonyl, naphthylsulfonyl, and the like, and the like),-   (43) a lower alkylcarbonylamino group (e.g., a C₁₋₆    alkylcarbonylamino group such as methylcarbonylamino, and the like,    and the like) and the like (to be referred to as substituent group A    in the present specification) is used.

The compound represented by the formula (I) is explained below. Unlessotherwise specified, the definition of each group is the same as thatmentioned above.

In the formula (I), R₁ is a hydrogen atom or a substituent. Here,examples of the “substituent” include an optionally substituted C₁₋₆alkyl group, an optionally substituted C₆₋₁₀ aryl group, a halogen atomand the like. The substituents for R₁ may be those exemplified as theabove-mentioned substituent group A. R₁ is preferably a hydrogen atom; aC₁₋₆ alkyl group (e.g., methyl, tert-butyl) optionally substituted by ahalogen atom (e.g., fluorine atom); a C₆₋₁₀ aryl group (e.g., phenyl)optionally substituted by one or more substituents selected from thegroup consisting of a halogen atom (e.g., a chlorine atom) and a C₁₋₆alkyl group (e.g., methyl); or a halogen atom (e.g., a chlorine atom).More preferably, R₁ is methyl.

In the formula (I), R₂ is a substituent. Here, examples of the“substituent” include an optionally substituted C₁₋₆ alkyl group, anoptionally substituted C₆₋₁₀ aryl group and the like. The substituentsfor R₂ may be those exemplified as the above-mentioned substituent groupA. R₂ is preferably an unsubstituted C₁₋₆ alkyl group (e.g., methyl) oran unsubstituted C₆₋₁₀ aryl group (e.g., phenyl). More preferably, R₂ ismethyl.

In the formula (I), R₃ is a hydrogen atom or a substituent. Here,examples of the “substituent” include an optionally substituted C₇₋₁₁aralkyl group, an optionally substituted C₆₋₁₀ aryl group, an optionallysubstituted C₁₋₆ alkyl group and the like. The substituents for R₃ maybe those exemplified as the above-mentioned substituent group A. R₃ ispreferably a hydrogen atom; a C₇₋₁₁ aralkyl group (e.g., benzyl,naphthylmethyl) optionally substituted by one or more substituentsselected from the group consisting of a halogen atom (e.g., chlorineatom, fluorine atom), a C₁₋₆ alkyl group (e.g., methyl, tert-butyl)optionally substituted by a halogen atom (e.g., fluorine atom), a C₆₋₁₀aryl group (e.g., phenyl) and a C₁₋₆ alkoxy group (e.g., methoxy); aC₆₋₁₀ aryl group (e.g., phenyl); or a C₁₋₆ alkyl group (e.g., methyl,hexyl) optionally substituted by one or more substituents selected fromthe group consisting of a C₆₋₁₀ aryl group (e.g., phenyl), a C₁₋₆alkoxy-carbonyl group (e.g., methoxycarbonyl), a carboxyl group and aC₃₋₆ cycloalkyl group (e.g., cyclohexyl). More preferably, R₃ is benzyl.

In the formula (I), R₄ is a hydrogen atom or a substituent. Here,examples of the “substituent” include an optionally substituted 01-6alkyl group and the like. The substituents for R₄ may be thoseexemplified as the above-mentioned substituent group A. R₄ is preferablya hydrogen atom.

Of the compounds represented by the formula (I), particularly preferredis a compound wherein

-   R₁ is-   a hydrogen atom;-   a C₁₋₆ alkyl group optionally substituted by a halogen atom (e.g.,    methyl, tert-butyl, trifluoromethyl);-   a C₆₋₁₀ aryl group optionally substituted by one or more    substituents selected from the group consisting of a halogen atom    and a C₁₋₆ alkyl group (e.g., phenyl, methylphenyl, chlorophenyl);    or-   a halogen atom (e.g., chlorine atom),-   R₂ is-   a C₁₋₆ alkyl group (e.g., methyl) or a C₆₋₁₀ aryl group (e.g.,    phenyl),-   R₃ is-   a hydrogen atom;-   a C₇₋₁₁ aralkyl group optionally substituted by one or more    substituents selected from the group consisting of a halogen atom, a    C₁₋₆ alkyl group optionally substituted by a halogen atom, a C₆₋₁₀    aryl group, and a C₁₋₆ alkoxy group (e.g., benzyl, naphthylmethyl,    tert-butylbenzyl, fluorobenzyl, chlorobenzyl, dichlorobenzyl,    trifluoromethylbenzyl, phenylbenzyl, methoxybenzyl);-   a C₆₋₁₀ aryl group (e.g., phenyl); or-   a C₁₋₆ alkyl group optionally substituted by one or more    substituents selected from the group consisting of a C₁₋₆    alkoxy-carbonyl group, a carboxyl group, and a C₃₋₆ cycloalkyl group    (e.g., methyl, hexyl, methoxycarbonylmethyl, carboxymethyl,    diphenylmethyl), and-   R₄ is a hydrogen atom.

Of compounds (I), still more preferred is a compound represented by

Among compounds (I), particularly, a compound wherein R₃ is not methylwhen R₁ is a hydrogen atom, and a compound wherein R₃ is not a hydrogenatom when R₁ is a substituent are novel compounds.

As a salt of compound (I), a pharmaceutically acceptable salt and thelike can be mentioned. Examples containing include an acid addition saltwith an acid such as trifluoroacetic acid, acetic acid, lactic acid,succinic acid, maleic acid, tartaric acid, citric acid, gluconic acid,ascorbic acid, benzoic acid, methanesulfonic acid, p-toluenesulfonicacid, cinnamic acid, fumaric acid, phosphonic acid, hydrochloric acid,nitric acid, hydrobromic acid, hydroiodic acid, sulfamic acid, sulfuricacid and the like; salts with metal such as sodium, potassium,magnesium, calcium and the like; a salt with an organic base such astrimethylamine, triethylamine, pyridine, picoline, N-methylpyrrolidine,N-methylpiperidine, N-methylmorpholine and the like, and the like.

When compound (I) has an isomer such as optical isomer, stereoisomer,positional isomer, rotamer and the like, any one of the isomers and amixture of isomers are also encompassed in compound (I). For example,when compound (I) has an optical isomer, an optical isomer resolved fromthe racemate is also encompassed in compound (I). These isomers can beeach obtained as a single product by a synthesis method, and aseparation method (concentration, solvent extraction, columnchromatography, recrystallization etc.) known per se. Also, compound (I)contains a structural isomer such as tautomer and the like and ageometric isomer. Such isomers are also within the scope of the presentinvention.

Examples of the tautomer include the following structures.

wherein each symbol is as defined above.

Compound (I) may be a crystal or an amorphous form. When compound (I) isa crystal, the crystal is encompassed in compound (I), whether thecrystal form is single or mixture of crystal forms. Crystals can beproduced by crystallization by applying a crystallization method knownper se.

Compound (I) may be a solvate (e.g., hydrate etc.) or a non-solvate,both of which are encompassed in compound (I).

Compound (I) may be labeled with an isotope (e. ³H, ¹⁴C, ³⁵S, ¹²⁵I etc.)and the like.

The compound of the present invention has a Prostate Cancer Antigen-1(PCA-1) binding activity, and has an action to inhibit the enzymeactivity of PCA-1. PCA-1 is a gene highly expressed specifically inprostate cancer and identified by the present inventors. Since this genehas a high homology to Escherichia coli protein AlkB, which is a DNA,RNA alkylation damage repair enzyme, it is also called human AlkBhomologue 3 (hALKBH3), and has recently been confirmed to catalyze DNA,RNA demethylation like AlkB. To inhibit the enzyme activity of PCA-1means to directly and/or indirectly inhibit DNA, RNA demethylationreaction of PCA-1. For example, the enzyme activity is inhibited byspecifically binding to PCA-1. The enzyme activity can be measuredaccording to the method generally performed in the field, or said methodmodified as necessary. For example, it can be evaluated by measuring thedegree of demethylation by using a methylated substrate DNA.

Due to the superior PCA-1 inhibitory activity of the compound of thepresent invention, the compound of the present invention is useful as aprophylactic or therapeutic drug for a disease, for which PCA-1 isinvolved in the onset and progression thereof (disease wherein onset orprogression is promoted), in mammals (e.g., human, monkey, cat, swine,horse, bovine, mouse, rat, guinea pig, dog, rabbit etc.).

Examples of such disease include cancer (e.g., prostate cancer,pancreatic cancer, non-small cell lung cancer), brain neurodegenerativedisease (e.g., Alzheimer, Parkinson), arteriosclerosis and the like.

The content of the compound of the present invention in a medicament(for example, anti-cancer agent etc.) containing the compound of thepresent invention as an active ingredient is generally about 0.01-about99.9 wt %, preferably about 0.1-about 50 wt %, relative to the wholepreparation.

The dose of the compound of the present invention is determined inconsideration of the age, body weight, general health condition, sex,diet, administration time, administration method, clearance rate,combination of drugs, and the level of the disease state for which thepatient is receiving the treatment then, or other factors.

While the dose varies depending on the target disease, symptom, subjectof administration, administration method and the like, for example, thecompound of the present invention is preferably administered in about0.1 100 mg/kg (body weight), preferably about 1-10 mg/kg (body weight),more preferably about 1-3 mg/kg (body weight), as the amount of compound(I), in once or 2 or 3 portions per day.

The compound of the present invention can be used in combination withother drugs according to the target disease. Such combination drug maybe a low-molecular-weight compound, or a high-molecular-weight protein,polypeptide, antibody or vaccine and the like. In this case, theadministration period of the compound of the present invention and thecombination drug is not limited, and the compound of the presentinvention and the combination drug only need to be combined at the timeof administration.

The compound of the present invention can be appropriately formulated asa solid preparation such as tablet, capsule, granule, powder and thelike; liquid preparation such as syrup, injection and the like; apercutaneous absorber such as adhesive preparation, ointment, plasterand the like; inhalant; or suppository, by blending with apharmaceutically acceptable carrier.

A medicament containing the compound of the present invention isadministered orally or parenterally, wherein only one kind of theabove-mentioned compound may be used singly, or two or more kindsthereof may be used in combination.

As the pharmaceutically acceptable carrier, various organic or inorganiccarrier substances conventionally used as preparation materials can beused. Specifically, excipient, lubricant, binder, disintegrant for solidpreparations, solvent, solubilizing agents, suspending agent, isotonicagent, buffering agent, soothing agent for liquid preparations and thelike can be blended. Also, where necessary, preparation additives suchas preservative, antioxidant, colorant, sweetening agent and the likecan also be used.

Examples of the excipient include lactose, sucrose, glucose, starch,saccharose, crystalline cellulose, Glycyrrhiza uralensis, mannitol,sodium hydrogen carbonate, calcium phosphate, calcium sulfate and thelike.

Examples of the lubricant include magnesium stearate, stearic acid,calcium stearate, purification talc, colloidal silica and the like.

Examples of the binder include crystalline cellulose, sucrose, mannitol,dextrin, hydroxypropylcellulose, hydroxypropylmethylcellulose,polyvinylpyrrolidone and the like.

Examples of the disintegrant include starch, carboxymethylcellulose,calcium carboxymethylcellulose, croscarmellose sodium, sodiumcarboxymethyl starch and the like.

Preferable examples of the solvent include water for injection, alcohol,propylene glycol, macrogol, sesame oil, corn oil and the like.

Preferable examples of the solubilizing agents include polyethyleneglycol, propylene glycol, D-mannitol, benzyl benzoate, ethanol,trisaminomethane, cholesterol, triethanolamine, sodium carbonate, sodiumcitrate and the like.

Examples of the suspending agent include surfactants such asstearyltriethanolamine, sodium lauryl sulfate, lauryl aminopropionicacid, lecithin, benzalkonium chloride, benzethonium chloride, glycerolmonostearate and the like; polyvinyl alcohol, polyvinylpyrrolidone,sodium carboxymethylcellulose, methylcellulose, hydroxymethylcellulose,hydroxyethylcellulose, hydroxypropylcellulose and the like.

Preferable examples of the isotonic agent include sodium chloride,glycerol, D-mannitol and the like.

Preferable examples of the buffering agent include buffer such asphosphate, acetate, carbonate and citrate and the like, and the like.

Preferable examples of the soothing agent include benzylalcohol and thelike.

Preferable examples of the preservative include paraoxybenzoates,chlorobutanol, benzyl alcohol, phenethyl alcohol, dehydroacetic acid,sorbic acid and the like.

Preferable examples of the antioxidant include sulfite, ascorbic acidand the like.

Preferable examples of the colorant include tar pigment, caramel, redferric oxide, titanium oxide, riboflavins and the like.

Preferable examples of the sweetening agent include glucose, fructose,invert sugar, sorbitol, xylitol, glycerol, simple syrup and the like.

Production Method

The compound represented by the formula (I), an isomer thereof, asolvate and a pharmaceutically acceptable salt thereof of the presentinvention can be produced by utilizing the features based on the basicskeleton or the kind of substituents and applying various knownsynthesis methods. For example, they can be produced according to, butnot limited to, the following synthesis methods, which can beappropriately modified when desired. As such modification, alkylation,acylation, amination, imination, halogenation, reduction, oxidation andthe like can be mentioned, and the reaction or method generally used inthe field is utilized. In this case, it is sometimes effective for theproduction technique to replace, depending on the kind of the functionalgroup, the functional group with a suitable protecting group (groupeasily converted to the functional group), in the stage of a startingmaterial or an intermediate. The chemical property of the protectinggroup, the method of introduction thereof, and removal thereof aredescribed in detail in, for example, T. Greene and P. Wuts “ProtectiveGroups in Organic Synthesis” (3^(rd) ed.), John Wiley & Sons NY (1999).

The starting compounds may be, unless particularly indicated, productswhich are easily available commercially, or can be produced according toa method known per se or a method analogous thereto.

In each reaction and each reaction for the synthesis of startingcompounds, generally known solvents may be used for the reaction.

Examples of the generally known solvents include ethers such astetrahydrofuran, diethyl ether, 1,2-dimethoxyethane, 1,4-dioxane and thelike, esters such as ethyl acetate, butyl acetate and the like, aromatichydrocarbons such as benzene, toluene and the like, aromatic heterocyclecompounds such as pyridine, lutidine and the like, amides such asN,N-dimethylformamide, N-methylpyrrolidone and the like, halides such aschloroform, methylene chloride and the like, alcohols such as methanol,ethanol, 2-propanol, 2,2-dimethylethanol and the like, hydrocarboncompounds such as hexane, heptane, petroleum ether and the like,carboxylic acids such as formic acid, acetic acid and the like, or waterand the like.

The solvent to be used for the reaction may be a single solvent or amixture of 2 to 6 kinds of solvents.

Also, reactions are sometimes performed in the co-presence of an aminesuch as triethylamine, N,N-diisopropylamine, pyridine,N-methylmorpholine and the like, or a base such as sodium hydroxide,potassium carbonate and the like.

Also, reactions are sometimes performed in the co-presence of, forexample, an acid such as hydrochloric acid, sulfuric acid, acetic acidand the like.

Production Method 1

The synthesis scheme of the compound of the present invention is shownbelow (detailed reactions follow Examples). In the scheme, a specificgroup or compound is described. It is clear to those of ordinary skillin the art that substitutable groups and compounds can be used.

wherein Et is ethyl and each of other symbols is as defined above.

In step 1, a benzimidazolone skeleton is formed via a cyclizationreaction. Such cyclization reaction can be performed by a reaction witha reagent such as carbonyldiimidazole (CDI) and the like.

In steps 2 and 3, a hydrazino group is introduced into the benzimidazoleskeleton. This reaction can be performed by chlorinating with achlorinating agent such as phosphoryl chloride and the like, followed bya reaction with hydrazine.

In step 4, a ring is further formed by a reaction of a hydrazinederivative with ketone.

All of them are performed by the methods generally carried out in thefield and an appropriate combination thereof.

EXAMPLES

The present invention is explained in detail in the following byreferring to Examples which are not to be construed as limitative. Thereagents and materials to be used are commercially available unlessparticularly limited.

Example 1 Synthesis of1-(5-methyl-1H-benzimidazol-2-yl)-3-methyl-4-(phenylmethyl)-1H-pyrazol-5-ol

(Step 1)

Synthesis of 5-methyl-1,3-dihydrobenzimidazol-2-one (2)

To a solution of 4-methyl-1,2-phenylenediamine (1) (25 g) intetrahydrofuran (375 mL) was added dropwise a solution of1,1′-carbonyldiimidazole (36.5 g) in dichloromethane (375 mL). Afterstirring at room temperature for 6.5 hr, diisopropylether (375 mL) wasadded to the reaction mixture. After stirring at room temperature, theresulting precipitate was collected by filtration. The precipitate waswashed with diisopropyl ether, and dried under reduced pressure to give5-methyl-1,3-dihydrobenzimidazol-2-one (2) (24.6 g).

ESI-HRMS (positive ion, sodium formate): calcd for C₈H₈N₂ONa([M+Na]⁺)171.0529. found 171.0529

NMR (DMSO-d₆, δ): 2.27 (3H, s), 6.70-6.81 (3H, m), 10.46 (2H, br s)

(Step 2)

Synthesis of 2-chloro-5-methyl-1H-benzimidazole (3)

A mixture of 5-methyl-1,3-dihydrobenzimidazol-2-one (2) (24.4 g) andphosphoryl chloride (245 mL) was stirred at 90° C. for 5 hr. Aftercooling to room temperature, chloroform (250 mL) was added to thereaction mixture. After stirring at room temperature, the resultingprecipitate was collected by filtration, and washed 5 times withchloroform (100 mL). To the precipitate was added a mixture of ethylacetate and saturated sodium hydrogen carbonate solution. After stirringat room temperature, the organic phase was successively washed withwater and brine, and dried over magnesium sulfate. The solvent wasevaporated under reduced pressure. The residue was powdered with hexaneand diisopropyl ether to give 2-chloro-5-methyl-1H-benzimidazole (3)(20.4 g).

ESI-HRMS (positive ion, sodium formate): calcd for C₈H₈ClN₂([M+H]⁺)167.0371. found 167.0391

NMR (DMSO-d₆, δ): 2.40 (3H, s), 7.00-7.06 (1H, m), 7.29 (1H, s), 7.39(1H, d, J=8.2 Hz)

(Step 3)

Synthesis of 2-hydrazino-5-methyl-1H-benzimidazole (4)

A mixture of 2-chloro-5-methyl-1H-benzimidazole (3) (10.2 g) andhydrazine 1 hydrate (59 mL) was stirred at 100° C. for 4 hr. Aftercooling to room temperature, water (60 mL) was added to the reactionmixture. After stirring under ice-cooling, the resulting precipitate wascollected by filtration. The precipitate was washed three times, andthen dried under reduced pressure to give2-hydrazino-5-methyl-1H-benzimidazole (4) (8.4 g).

ESI-HRMS (positive ion, sodium formate): calcd for C₈H₁₁N₄([M+H]⁺)163.0978. found 163.0985

NMR (DMSO-d₆, δ): 2.30 (3H, s), 4.39 (2H, br s), 6.63-6.70 (1H, m),6.91-6.94 (1H, m), 6.97-7.01 (1H, m), 7.69 (1H, br s), 10.87 (1H, br s)

(Step 4)

Synthesis of3-methyl-1-(5-methyl-1H-benzimidazol-2-yl)-4-(phenylmethyl)-1H-pyrazol-5-ol(5)

A mixture of 2-hydrazino-5-methyl-1H-benzimidazole (4) (1.0 g) and ethyl2-acetyl-3-phenylpropanoate (1.4 mL) in acetic acid (20 mL) was stirredat room temperature for 2 hr. The reaction mixture was added to amixture of acetonitrile (100 mL) and water (100 mL). After stirring atroom temperature, the resulting precipitate was collected by filtration,and washed with a mixture of acetonitrile and water (1:1). Theprecipitate was recrystallized from ethanol (95 mL) to give3-methyl-1-(5-methyl-1H-benzimidazol-2-yl)-4-(phenylmethyl)-1H-pyrazol-5-ol(5) (0.64 g).

ESI-HRMS (positive ion, sodium formate): calcd for C₁₉H₁₉N₄O([M+H]⁺)319.1559. found 319.1588

NMR (DMSO-d₆, δ): 2.15 (3H, s), 2.39 (3H, s), 3.59 (2H, s), 6.96-7.00(1H, m), 7.13-7.20 (1H, m), 7.23-7.29 (4H, m), 7.31 (1H, br s), 7.39(1H, d, J=8.2 Hz)

IR(KBr): 3312, 3024, 2936, 2915, 1653, 1553 cm⁻¹

Melting point: 205-208° C.

HPLC retention time: 11.2 min

HPLC gradient condition: CH₃CN/0.1% TFA; CH₃CN (%)/min: 10/0, 10/1,90/11, 90/15, 10/15.1, 10/20

Example 2 Synthesis of3-methyl-1-(4-methyl-1H-benzimidazol-2-yl)-4-(phenylmethyl)-1H-pyrazol-5-ol(10)

(Step 1)

Synthesis of 4-methyl-1,3-dihydrobenzimidazol-2-one (7)

Using 3-methyl-1,2-phenylenediamine (6) and by a method similar to thatin Example 1, step 1, 4-methyl-1,3-dihydrobenzimidazol-2-one (7) wasobtained.

ESI-HRMS (positive ion, sodium formate): calcd for C₈H₈N₂ONa([M+Na]⁺)171.0529. found 171.0529

NMR (MeOH-d₄, δ): 2.33 (3H, s), 6.83 (1H, d, J=7.8 Hz), 6.86 (1H, d,J=7.4 Hz), 6.89-6.95 (1H, m)

(Step 2)

Synthesis of 2-chloro-4-methyl-1H-benzimidazole (8)

Using 4-methyl-1,3-dihydrobenzimidazol-2-one (7) and by a method similarto that in Example 1, step 2, 2-chloro-4-methyl-1H-benzimidazole (8) wasobtained.

ESI-HRMS (positive ion, sodium formate): calcd for C₈H₇ClN₂([M+H]⁺)167.0370. found 167.0375

NMR (MeOH-d₄, δ): 2.50 (3H, s), 7.04 (1H, d, J=7.4 Hz), 7.11-7.17 (1H,m), 7.30 (1H, d, J=8.2 Hz)

(Step 3)

Synthesis of 2-hydrazino-4-methyl-1H-benzimidazole (9)

Using 2-chloro-4-methyl-1H-benzimidazole (8) and by a method similar tothat in Example 1, step 3, 2-hydrazino-4-methyl-1H-benzimidazole (9) wasobtained.

ESI-HRMS (positive ion, sodium formate): calcd for C₈H₁₀N₄([M+H]⁺)163.0978. found 163.1009

NMR (MeOH-d₄, δ): 2.43 (3H, s), 6.79 (1H, d, J=7.3 Hz), 6.84-6.91 (1H,m), 7.06 (1H, d, J=7.8 Hz)

(Step 4)

3-methyl-1-(4-methyl-1H-benzimidazol-2-yl)-4-(phenylmethyl)-1H-pyrazol-5-ol(10)

Using 2-hydrazino-4-methyl-1H-benzimidazole (9) and in the same manneras in Example 1, step 4,3-methyl-1-(4-methyl-1H-benzimidazol-2-yl)-4-(phenylmethyl)-1H-pyrazol-5-ol(10) was obtained.

ESI-HRMS (positive ion, sodium formate): calcd for C₁₉H₁₉N₄O([M+H]⁺)319.1559. found 319.1562

NMR (DMSO-d₆, δ): 2.18 (3H, s), 2.52 (3H, s), 3.61 (2H, s), 6.95-6.99(1H, m), 7.05 (1H, t, J=7.8 Hz), 7.13-7.21 (1H, m), 7.22-7.30 (4H, m),7.35 (1H, d, 3=7.8 Hz)

IR(KBr): 3272, 3027, 1667, 1628, 1575 cm⁻¹

HPLC retention time: 11.9 min

Example 3 Synthesis of1-(5-chloro-1H-benzimidazol-2-yl)-3-methyl-4-(phenylmethyl)-1H-pyrazol-5-ol(15)

(Step 1)

Synthesis of 5-chloro-1,3-dihydrobenzimidazol-2-one (12)

Using 4-chloro-1,2-phenylenediamine (11) and by a method similar to thatin Example 1, step 1, 5-chloro-1,3-dihydrobenzimidazol-2-one (12) wasobtained.

ESI Mass: 191.0[M+Na]⁺ (positive)

NMR (DMSO-d₆, δ): 6.89-6.97 (3H, m), 10.75 (2H, br s)

(Step 2)

Synthesis of 2,5-dichloro-1H-benzimidazole (13)

Using 5-chloro-1,3-dihydrobenzimidazol-2-one (12) and by a methodsimilar to that in Example 1, step 2,2,5-dichloro-1H-benzimidazole (13)was obtained.

ESI Mass: 187.0[M+H]⁺ (positive)

NMR (MeOH-d₄, δ): 7.26 (1H, dd, J=1.8 and 8.7 Hz), 7.46 (1H, d, J=8.7Hz), 7.51 (1H, d, J=1.8 Hz)

(Step 3)

Synthesis of 5-chloro-2-hydrazino-1H-benzimidazole (14)

Using 2,5-dichloro-1H-benzimidazole (13) and by a method similar to thatin Example 1, step 3, 5-chloro-2-hydrazino-1H-benzimidazole (14) wasobtained.

ESI-HRMS (positive ion, sodium formate): calcd for C₇H₈ClN₄([M+H]⁺)183.0432. found 183.0442

NMR (DMSO-d₆, δ): 4.49 (2H, br s), 6.76-6.93 (1H, m), 7.03-7.14 (2H, m),7.98 (1h, br s), 11.15 (1H, br s)

(Step 4)

Synthesis of1-(5-chloro-1H-benzimidazol-2-yl)-3-methyl-4-(phenylmethyl)-1H-pyrazol-5-ol(15)

Using 5-chloro-2-hydrazino-1H-benzimidazole (14) and in the same manneras in Example 1, step 4,1-(5-chloro-1H-benzimidazol-2-yl)-3-methyl-4-(phenylmethyl)-1H-pyrazol-5-ol(15) was obtained.

ESI-HRMS (positive ion, sodium formate): calcd for C₁₈H₁₆ClN₄O([M+H]⁺)339.1007. found 339.0978

NMR (DMSO-d₆, δ): 2.17 (3H, s), 3.59 (2H, s), 7.13-7.21 (2H, m),7.24-7.30 (4H, m), 7.52 (1H, d, J=8.7 Hz), 7.55 (1H, d, J=2.3 Hz)

IR(KBr): 3263, 3031, 2914, 2842, 1654, 1623, 1556 cm⁻¹

HPLC retention time: 13.1 min

Example 4 Synthesis of3-methyl-4-(phenylmethyl)-1-(5-trifluoromethyl-1H-benzimidazol-2-yl)-1H-pyrazol-5-ol(20)

(Step 1)

Synthesis of 5-trifluoromethyl-1,3-dihydrobenzimidazol-2-one (17)

Using 4-trifluoromethyl-1,2-phenylenediamine (16) and by a methodsimilar to that in Example 1, step1,5-trifluoromethyl-1,3-dihydrobenzimidazol-2-one (17) was obtained.

ESI Mass: 225.0[M+Na]⁺ (positive)

NMR (DMSO-d₆, δ): 7.08 (1H, d, J=8.2 Hz), 7.15 (1H, s), 7.28 (1H, d,J=8.2 Hz), 10.99 (2H, br s)

(Step 2)

Synthesis of 2-chloro-5-trifluoromethyl-1H-benzimidazole (18)

Using 5-trifluoromethyl-1,3-dihydrobenzimidazol-2-one (17) and by amethod similar to that in Example 1, step 2,2-chloro-5-trifluoromethyl-1H-benzimidazole (18) was obtained.

ESI-HRMS (positive ion, sodium formate): calcd for C₈H₅ClF₃N₂([N+H]⁺)221.0088. found 221.0098

NMR (DMSO-d₆, δ): 7.54 (1H, d, J=8.2 Hz), 7.70 (1H, d, J=8.2 Hz), 7.88(1H, s)

(Step3)

Synthesis of 2-hydrazino-5-trifluoromethyl-1H-benzimidazole (19)

Using 2-chloro-5-trifluoromethyl-1H-benzimidazole (18) and by a methodsimilar to that in Example 1, step3,2-hydrazino-5-trifluoromethyl-1H-benzimidazole (19) was obtained.

ESI-HRMS (positive ion, sodium formate); calcd for C₈H₈F₃N₄([M+H]⁺)217.0696. found 217.0692

NMR (MeOH-d₄, δ): 7.25-7.39 (2H, m), 7.48-7.53 (1H, m)

(Step 4)

Synthesis of3-methyl-4-(phenylmethyl)-1-(5-trifluoromethyl-1H-benzimidazol-2-yl)-1H-pyrazol-5-ol(20)

Using 2-hydrazino-5-trifluoromethyl-1H-benzimidazole (19) and in thesame manner as in Example 1, step 4,3-methyl-4-(phenylmethyl)-1-(5-trifluoromethyl-1H-benzimidazol-2-yl)-1H-pyrazol-5-ol(20) was obtained.

ESI-HRMS (positive ion, sodium formate); calcd for C₁₉H₁₆F₃N₄O([M+H]⁺)373.1271. found 373.1259

NMR (DMSO-d₆, δ): 2.19 (3H, s), 3.60 (2H, s), 7.14-7.21 (1H, m),7.24-7.31 (4H, m), 7.46-7.52 (1H, m), 7.70 (1H, d, J=8.2 Hz), 7.84 (1H,s)

IR(KBr): 3033, 2935, 2901, 1637, 1551 cm⁻¹

HPLC retention time: 13.6 min

Example 5 Synthesis of1-[5-(1,1-dimethylethyl)-1H-benzimidazol-2-yl]-3-methyl-4-(phenylmethyl)-1H-pyrazol-5-ol(25)

(Step 1)

Synthesis of 5-(1,1-dimethylethyl)-1,3-dihydrobenzimidazol-2-one (22)

Using 4-(1,1-dimethylethyl)-1,2-phenylenediamine (21) and by a methodsimilar to that in Example 1, step 1,5-(1,1-dimethylethyl)-1,3-dihydrobenzimidazol-2-one (22) was obtained.

ESI Mass: 191.1[M+H]⁺ (positive)

NMR (DMSO-d₅, δ): 1.26 (9H, s), 6.83 (1H, d, J=7.8 Hz), 6.91 (1H, s),6.94-6.97 (1H, m), 10.44 (2H, br s)

(Step 2)

Synthesis of 2-chloro-5-(1,1-dimethylethyl)-1H-benzimidazole (23)

Using 5-(1,1-dimethylethyl)-1,3-dihydrobenzimidazol-2-one (22) and by amethod similar to that in Example 1, step 2,2-chloro-5-(1,1-dimethylethyl)-1H-benzimidazole (23) was obtained.

ESI Mass: 209.1[M+H]⁺ (positive)

NMR (DMSO-d₆, δ): 1.31 (9H, s), 7.25-7.44 (3H, m)

(Step 3)

Synthesis of 5-(1,1-dimethylethyl)-2-hydrazino-1H-benzimidazole (24)

Using 2-chloro-5-(1,1-dimethylethyl)-1H-benzimidazole (23) and by amethod similar to that in Example 1, step 3,5-(1,1-dimethylethyl)-2-hydrazino-1H-benzimidazole (24) was obtained.

ESI-HRMS (positive ion, sodium formate): calcd for C₁₁H₁₇N₄([M+H]⁺)205.1448. found 205.1458

NMR (DMSO-d₆, δ): 1.29 (9H, s), 6.87-7.95 (3H, m)

(Step 4)

Synthesis of1-[5-(1,1-dimethylethyl)-1H-benzimidazol-2-yl]-3-methyl-4-(phenylmethyl)-1H-pyrazol-5-ol(25)

Using 5-(1,1-dimethylethyl)-2-hydrazino-1H-benzimidazole (24) and in thesame manner as in Example 1, step 4,1-[5-(1,1-dimethylethyl)-1H-benzimidazol-2-yl]-3-methyl-4-(phenylmethyl)-1H-pyrazol-5-ol(25) was obtained.

ESI-HRMS (positive ion, sodium formate): calcd for C₂₂H₂₅N₄O([M+H]⁺)361.2023. found 361.2029

NMR (DMSO-d₆, δ): 1.33 (9H, s), 2.15 (3H, s), 3.59 (2H, s), 7.13-7.20(1H, m), 7.22-7.30 (5H, m), 7.43 (1H, d, J=8.2 Hz), 7.51 (1H, br s)

IR(KBr): 3026, 2961, 2903, 1655, 1558 cm⁻¹

HPLC retention time: 12.5 min

Example 6 Synthesis of 1-(4,5-dimethyl1H-benzimidazol-2-yl)-3-methyl-4-(phenylmethyl)-1H-pyrazol-5-ol (30)

(Step 1)

Synthesis of 4,5-dimethyl-1,3-dihydrobenzimidazol-2-one (27)

Using 4,5-dimethyl-1,2-phenylenediamine (26) and by a method similar tothat in Example 1, step 1,4,5-dimethyl-1,3-dihydrobenzimidazol-2-one(27) was obtained.

ESI-HRMS (positive ion, sodium formate): calcd for C₉H₁₁N₂O([M+H]⁺)163.0866. found 163.0850

NMR (DMSO-d₅, δ): 2.16 (3H, s), 2.18 (3H, s), 6.63 (1H, d, J=7.8 Hz),6.72 (1H, d, J=7.8 Hz), 10.40 (1H, s), 10.55 (1H, s)

(Step 2)

Synthesis of 2-chloro-4,5-dimethyl-1H-benzimidazole (28)

Using 4,5-dimethyl-1,3-dihydrobenzimidazol-2-one (27) and by a methodsimilar to that in Example 1, step 2,2-chloro-4,5-dimethyl-1H-benzimidazole (28) was obtained.

NMR (DMSO-d₆, δ): 2.30 (3H, s), 2.37 (3H, s), 7.02 (1H, d, J=8.2 Hz),7.20 (1H, d, J=8.2 Hz)

(Step 3)

Synthesis of 2-hydrazino-4,5-dimethyl-1H-benzimidazole (29)

Using 2-chloro-4,5-dimethyl-1H-benzimidazole (28) and by a methodsimilar to that in Example 1, step 3,2-hydrazino-4,5-dimethyl-1H-benzimidazole (29) was obtained.

ESI-HRMS (positive ion, sodium formate): calcd for C₉H₁₃N₄([M+H]⁺)177.1135. found 177.1169

NMR (DMSO-d₆, δ): 2.22 (3H, s), 2.28 (3H, s), 4.36 (2H, br s), 6.56-6.73(1H, m), 6.81 (1H, d, J=7.8 Hz), 7.61 (1H, br s), 10.80 (1H, br s)

(Step 4)

Synthesis of1-(4,5-dimethyl-1H-benzimidazol-2-yl)-3-methyl-4-(phenylmethyl)-1H-pyrazol-5-ol(30)

Using 2-hydrazino-4,5-dimethyl-1H-benzimidazole (29) and in the samemanner as in Example 1, step 4,1-(4,5-dimethyl-1H-benzimidazol-2-yl)-3-methyl-4-(phenylmethyl)-1H-pyrazol-5-ol(30) was obtained.

ESI-HRMS (positive ion, sodium formate): calcd for C₂₀H₂₁N₄O([M+H]⁺)333.1710. found 333.1726

NMR (DMSO-d₆, δ): 2.17 (3H, s), 2.31 (3H, s), 2.44 (3H, s), 3.61 (2H,s), 6.96 (1H, d, J=7.8 Hz), 7.12-7.30 (6H, m)

IR(KBr): 3026, 2920, 2866, 1677, 1600 cm⁻¹

HPLC retention time: 12.1 min

Example 7 Synthesis of4-[(4-chlorophenyl)methyl]-3-methyl-1-(5-methyl-1H-benzimidazol-2-yl)-1H-pyrazol-5-ol(32)

(Step 1)

Synthesis of ethyl 2-acetyl-3-(4-chlorophenyl)propanoate (31)

Using 4-chlorobenzylbromide and in the same manner as in Example 9, step1, ethyl 2-acetyl-3-(4-chlorophenyl)propanoate (31) was obtained.

ESI-HRMS (positive ion, sodium formate): calcd for C₁₃H₁₅ClO₃Na([M+Na]⁺)277.0602. found 277.0594

NMR (CDCl₃, δ): 1.19-1.24 (3H, m), 2.20 (3H, s), 3.06-3.18 (2H, m),3.70-3.76 (1H, m), 4.09-4.21 (2H, m), 7.09-7.14 (2H, m), 7.21-7.26 (2H,m)

(Step 2)

Synthesis of4-[(4-chlorophenyl)methyl]-3-methyl-1-(5-methyl-1H-benzimidazol-2-yl)-1H-pyrazol-5-ol(32)

Using 2-hydrazino-5-methyl-1H-benzimidazole (4) obtained in Example 1,step 3 and ethyl 2-acetyl-3-(4-chlorophenyl)propanoate (31), and by amethod similar to that in Example 1, step 4,4-[(4-chlorophenyl)methyl]-3-methyl-1-(5-methyl-1H-benzimidazol-2-yl)-1H-pyrazol-5-ol(32) was obtained.

ESI-HRMS (positive ion, sodium formate): calcd for C₁₉H₁₈ClN₄O([M+H]⁺)353.1164. found 353.1151

NMR (DMSO-d₆, δ): 2.15 (3H, s), 2.39 (3H, s), 3.58 (2H, s), 6.98 (1H,dd, J=0.9 and 8.2 Hz), 7.27-7.35 (5H, m), 7.39 (1H, d, J=8.2 Hz)

IR(KBr): 3032, 2921, 2864, 1665, 1552 cm⁻¹

HPLC retention time: 12.0 min

Example 8 Synthesis of3-methyl-1-(5-methyl-1H-benzimidazol-2-yl)-4-[(4-phenylphenyl)methyl]-1H-pyrazol-5-ol(34)

(Step 1)

Synthesis of ethyl 2-acetyl-3-(4-phenylphenyl)propanoate (33)

Using 4-phenylbenzylbromide and in the same manner as in Example 9, step1, ethyl 2-acetyl-3-(4-phenylphenyl)propanoate (33) was obtained.

ESI-HRMS (positive ion, sodium formate): calcd for C₁₉H₂₀O₃Na([M+Na]⁺)319.1310. found 319.1336

NMR (CDCl₃, δ): 1.22 (3H, t, J=7.3 Hz), 2.22 (3H, s), 3.15-3.25 (2H, m),3.78-3.84 (1H, m), 4.10-4.23 (2H, m), 7.23-7.27 (2H, m), 7.30-7.35 (1H,m), 7.39-7.45 (2H, m), 7.48-7.53 (2H, m), 7.54-7.58 (2H, m)

(Step 2)

Synthesis of3-methyl-1-(5-methyl-1H-benzimidazol-2-yl)-4-[(4-phenylphenyl)methyl]-1H-pyrazol-5-ol(34)

Using 2-hydrazino-5-methyl-1H-benzimidazole (4) obtained in Example 1,step 3 and ethyl 2-acetyl-3-(4-phenylphenyl)propanoate (33), and by amethod similar to that in Example 1, step 4,3-methyl-1-(5-methyl-1H-benzimidazol-2-yl)-4-[(4-phenylphenyl)methyl]-1H-pyrazol-5-ol(34) was obtained.

ESI-HRMS (positive ion, sodium formate): calcd for C₂₅H₂₃N₄O([M+H]⁺)395.1866. found 395.1834

NMR (DMSO-d₆, δ): 2.19 (3H, s), 2.39 (3H, s), 3.63 (2H, s), 6.96-7.00(1H, m), 7.30-7.47 (7H, m), 7.54-7.64 (4H, m)

IR(KBr): 3246, 3031, 2922, 2864, 1656, 1557, 1541 cm⁻¹

HPLC retention time: 12.7 min

Example 9 Synthesis of4-[(3,4-dichlorophenyl)methyl]-3-methyl-1-(5-methyl-1H-benzimidazol-2-yl)-1H-pyrazol-5-ol(36)

(Step 1)

Synthesis of ethyl 2-acetyl-3-(3,4-dichlorophenyl)propanoate (35)

To a solution of ethyl acetoacetate (1.0 g) in tetrahydrofuran (20 mL)was added sodium hydride (about 60% oil suspension) (0.37 g) in severalportions under ice-cooling under a nitrogen atmosphere. After stirringat room temperature for 1 hr, 3,4-dichlorobenzylbromide (1.4 mL) wasadded to the reaction mixture. After stirring at room temperature for 2hr, the reaction mixture was poured into a mixture of ethyl acetate andwater. The organic phase was washed successively with water and brine,and dried over magnesium sulfate. The solvent was evaporated underreduced pressure, and the residue was purified by column chromatographyon silica gel by eluting with toluene. An eluted fraction containing thedesired product was recovered and evaporated under reduced pressure togive ethyl 2-acetyl-3-(3,4-dichlorophenyl)propanoate (35) (1.6 g).

ESI-HRMS (positive ion, sodium formate): calcd forC₁₃H₁₄Cl₂O₃Na([M+Na]⁺) 311.0212. found 311.0203

NMR (CDCl₃, δ): 1.19-1.25 (3H, m), 2.23 (3H, s), 3.04-3.16 (2H, m),3.69-3.75 (1H, m), 4.11-4.23 (2H, m), 6.97-7.05 (1H, m), 7.22-7.36 (2H,m)

(Step 2)

Synthesis of4-[(3,4-dichlorophenyl)methyl]-3-methyl-1-(5-methyl-1H-benzimidazol-2-yl)-1H-pyrazol-5-ol(36)

Using 2-hydrazino-5-methyl-1H-benzimidazole (4) obtained in Example 1,step 3 and ethyl 2-acetyl-3-(3,4-dichlorophenyl)propanoate (35), and bya method similar to that in Example 1, step 4,4-[(3,4-dichlorophenyl)methyl]-3-methyl-1-(5-methyl-1H-benzimidazol-2-yl)-1H-pyrazol-5-ol(36) was obtained.

ESI-HRMS (positive ion, sodium formate): calcd for C₁₉H₁₆Cl₂N₄O([M+H]⁺)387.0779. found 387.0748

NMR (DMSO-d₆, δ): 2.17 (3H, s), 2.39 (3H, s), 3.60 (2H, s), 6.98 (1H,dd, J=0.9 and 8.2 Hz), 7.27 (1H, dd, J=1.8 and 8.2 Hz), 7.32 (1H, br s),7.39 (1H, d, J=8.2 Hz), 7.52 (1H, d, J=8.2 Hz), 7.55 (1H, d, J=1.8 Hz)

IR(KBr): 3050, 2922, 2865, 1665, 1561 cm⁻¹

HPLC retention time: 12.7 min

Example 10 Synthesis of3-methyl-1-(5-methyl-1H-benzimidazol-2-yl)-4-[(4-trifluorophenyl)methyl]-1H-pyrazol-5-ol(38)

(Step 1)

Synthesis of ethyl 2-acetyl-3-(4-trifluorophenyl)propanoate (37)

Using 4-trifluorobenzylbromide and in the same manner as in Example 9,step 1, ethyl 2-acetyl-3-(4-trifluorophenyl)propanoate (37) wasobtained.

ESI-HRMS (positive ion, sodium formate): calcd for C₁₃H₁₅F₃O₃Na([M+Na]₊)311.0866. found 311.0878

NMR (CDC₃, δ): 1.21 (3H, t, J=7.1 Hz), 2.22 (3H, s), 3.15-3.27 (2H, m),3.74-3.80 (1H, m), 4.10-4.22 (2H, m), 7.28-7.32 (2H, m), 7.51-7.55 (2H,m)

(Step2)

Synthesis of3-methyl-1-(5-methyl-1H-benzimidazol-2-yl)-4-[(4-trifluorophenyl)methyl]-1H-pyrazol-5-ol(38)

Using 2-hydrazino-5-methyl-1H-benzimidazole (4) obtained in Example 1,step 3 and ethyl 2-acetyl-3-(4-trifluorophenyl)propanoate (37), and by amethod similar to that in Example 1, step 4,3-methyl-1-(5-methyl-1H-benzimidazol-2-yl)-4-[(4-trifluorophenyl)methyl]-1H-pyrazol-5-ol(38) was obtained.

ESI-HRMS (positive ion, sodium formate): calcd for C₂₀H₁₈F₃N₄O([M+H]⁺)387.1433. found 387.1414

NMR (DMSO-d₆, δ): 2.17 (3H, s), 2.39 (3H, s), 3.69 (2H, s), 6.99 (1H,dd, J=0.9 and 8.2 Hz), 7.32 (1H, br s), 7.39 (1H, d, J=8.2 Hz), 7.50(2H, d, J=8.2 Hz), 7.64 (2H, d, J=8.2 Hz)

IR(KBr): 3268, 2923, 2865, 1666, 1552 cm⁻¹

HPLC retention time: 12.4 min

Example 11 Synthesis of3-methyl-1-(5-methyl-1H-benzimidazol-2-yl)-4-(2-naphthylmethyl)-1H-pyrazol-5-ol(40)

(Step 1)

Synthesis of ethyl 2-acetyl-3-(2-naphthyl)propanoate (39)

Using naphthylmethylbromide and in the same manner as in Example 9, step1, ethyl 2-acetyl-3-(2-naphthyl)propanoate (39) was obtained.

ESI-HRMS (positive ion, sodium formate): calcd for C₁₇H₁₈O₃Na([M+Na]⁺)293.1148. found 293.1141

NMR (CDC₃, δ): 1.13-1.21 (3H, m), 2.20 (3H, s), 3.27-3.38 (2H, m), 3.88(1H, t, J=7.8 Hz), 4.08-4.21 (2H, m), 7.28-7.34 (1H, m), 7.40-7.48 (2H,m), 7.63 (1H, s), 7.72-7.82 (3H, m)

(Step 2)

Synthesis of3-methyl-1-(5-methyl-1H-benzimidazol-2-yl)-4-(2-naphthylmethyl)-1H-pyrazol-5-ol(40)

Using 2-hydrazino-5-methyl-1H-benzimidazole (4) obtained in Example 1,step 3 and ethyl 2-acetyl-3-(2-naphthyl)propanoate (39), and by a methodsimilar to that in Example 1, step 4,3-methyl-1-(5-methyl-1H-benzimidazol-2-yl)-4-(2-naphthylmethyl)-1H-pyrazol-5-ol(40) was obtained.

ESI-HRMS (positive ion, sodium formate): calcd for C₂₃H₂₀N₄ONa([M+Na]⁺)391.1529. found 391.1516

NMR (DMSO-d₆, δ): 2.19 (3H, s), 2.39 (3H, s), 3.77 (2H, s), 6.98 (1H, d,J=7.8 Hz), 7.32 (1H, br s), 7.37-7.50 (4H, m), 7.74 (1H, br s),7.78-7.88 (3H, m)

IR(KBr): 3331, 3057, 2982, 2922, 1636, 1558 cm⁻¹

HPLC retention time: 12.2 min

Example 12 Synthesis of4-[[(1,1-dimethylethyl)phenyl]methyl]-3-methyl-1-(5-methyl-1H-benzimidazol-2-yl)-1H-pyrazol-5-ol(42)

(Step 1)

Synthesis of ethyl 2-acetyl-3-[(1,1-dimethylethyl)phenyl]propanoate (41)

Using 4-1,1-dimethylethylbenzylbromide and in the same manner as inExample 9, step 1, ethyl2-acetyl-3-[(1,1-dimethylethyl)phenyl]propanoate (41) was obtained.

ESI-HRMS (positive ion, sodium formate): calcd for C₁₇H₂₄O₃Na([M+Na]⁺)299.1617. found 299.1628

NMR (CDC₃, δ): 1.19 (3H, t, J=7.3 Hz), 1.28 (9H, s), 2.19 (3H, s), 3.13(2H, d, J=7.3 Hz), 3.76 (1H, t, J=7.3 Hz), 4.15 (2H, q, J=7.3 Hz),7.07-7.13 (2H, m), 7.26-7.37 (2H, m)

(Step 2)

Synthesis of4-[[(1,1-dimethylethyl)phenyl]methyl]-3-methyl-1-(5-methyl-1H-benzimidazol-2-yl)-1H-pyrazol-5-ol(42)

Using 2-hydrazino-5-methyl-1H-benzimidazole (4) obtained in Example 1,step 3 and ethyl 2-acetyl-3-[(1,1-dimethylethyl)phenyl]propanoate (41),and by a method similar to that in Example 1, step 4,4-[[(1,1-dimethylethyl)phenyl]methyl]-3-methyl-1-(5-methyl-1H-benzimidazol-2-yl)-1H-pyrazol-5-ol(42) was obtained.

ESI-HRMS (positive ion, sodium formate): calcd for C₂₃H₂₆N₄O([M+H]⁺)375.2179. found 375.2184

NMR (DMSO-d₆, δ): 1.24 (9H, s), 2.16 (3H, s), 2.39 (3H, s), 3.54 (2H,s), 6.98 (1H, dd, J=0.9 and 8.2 Hz), 7.17-7.21 (2H, m), 7.25-7.29 (2H,m), 7.31 (1H, br s), 7.39 (1H, d, J=8.2 Hz)

IR(KBr): 3233, 3024, 2961, 2865, 1658, 1558 cm⁻¹

HPLC retention time: 13.1 min

Using the corresponding starting compounds and in the same manner as inExample 1, the compounds of Examples 13-48 were synthesized. Thefollowing Tables summarize the structures of Examples 1-48 andphysicochemical properties thereof.

TABLE 1 HPLC reten- tion Ex. time purity No. 1H-NMR IR ESI-HRMS (mm) (%) 1

NMR (DMSO-d₆, δ): 2.15 (3H, s), 2.39 (3H, s), 3.59 (2H, s), 6.96-7.00(1H, m), 7.13-7.20 (1H, m), 7.23-7.29 (4H, m), 7.31 (1H, br s), 7.39(1H, d, J = 8.2 Hz) IR (KBr): 3312, 3024, 2936, 2915, 1653, 1553 cm⁻¹ESI-HRMS (positive ion, sodium formate) calcd for C₁₈H₁₈N₄O ([M + H]⁺)319.1559; found 319.1588 11.2 99.4  2

NMR (DMSO-d₆, δ): 2.18 (3H, s), 2.52 (3H, s), 3.61 (2H, s), 6.95-6.99(1H, m), 7.05 (1H, t, J = 7.8 Hz), 7.13-7.21 (1H, m), 7.22- 7.30 (4H,m), 7.35 (1H, d, J = 7.8 Hz) IR (KBr): 3272, 3027, 1667, 1628, 1575 cm⁻¹ESI-HRMS (positive ion, sodium formate) calcd for C₁₈H₁₈N₄O ([M + H]⁺)319.1559; found 319.1562 11.9 98.6  3

NMR (DMSO-d₆, δ): 2.17 (3H, s), 3.59 (2H, s), 7.13- 7.21 (2H, m),7.24-7.30 (4H, m), 7.52 (1H, d, J = 8.7 Hz), 7.55 (1H, d, J = 2.3 Hz) IR(KBr): 3263, 3031, 2914, 2842, 1654, 1623, 1556 cm⁻¹ ESI-HRMS (positiveion, sodium formate) calcd for C₁₈H₁₅ClN₄O ([M + H]⁺) 339.1007; found339.0978 13.1 98.9  4

NMR (DMSO-d₆, δ): 2.19 (3H, s), 3.60 (2H, s), 7.14- 7.21 (1H, m),7.24-7.31 (4H, m), 7.46-7.52 (1H, m), 7.70 (1H, d, J = 8.2 Hz), 7.84(1H,s) IR (KBr): 3033, 2935, 2901, 1637, 1551 cm⁻¹ ESI-HRMS (positive ion,sodium formate) calcd for C₁₉H₁₆F₃N₄O ([M + H]⁺) 373.1271; found373.1259 13.6 98.8  5

NMR (DMSO-d₆, δ): 1.33 (9H, s), 2.15 (3H, s), 3.59 (2H, s), 7.13-7.20(1H, m), 7.22-7.30 (5H, m), 7.43 (1H, d, J = 8.2 Hz), 7.51 (1H, br s) IR(KBr): 3026, 2961, 2903, 1655, 1558 cm⁻¹ ESI-HRMS (positive ion, sodiumformate) calcd for C₂₂H₂₅N₄O ([M + H]⁺) 361.2023; found 361.2029 12.597.9  6

NMR (DMSO-d₆, δ): 2.17 (3H, s), 2.31 (3H, s), 2.44 (3H, s), 3.61 (2H,s), 6.96 (1H, d, J = 7.8 Hz), 7.12- 7.30 (6H, m) IR (KBr): 3026, 2920,2866, 1677, 1600 cm⁻¹ ESI HRMS (positive ion, sodium formate) calcd forC₂₀H₂₁N₄O ([M + H]⁺) 333.1710; found 333.1726 12.1 97.4  7

NMR (DMSO-d₆, δ): 2.15 (3H, s), 2.39 (3H, s), 3.58 (2H, s), 6.98 (1H,dd, J = 0.9 and 8.2 Hz), 7.27-7.35 (5H, m), 7.39 (1H, d, J = 8.2 Hz) IR(KBr): 3032, 2921, 2864, 1665, 1552 cm⁻¹ ESI HRMS (positive ion, sodiumformate) calcd for C₁₈H₁₈ClN₄O ([M + H]⁺) 353.1164; found 353.1151 12.098.1  8

NMR (DMSO-d₆, δ): 2.19 (3H, s), 2.39 (3H, s), 3.63 (2H, s), 6.96-7.00(1H, m), 7.30-7.47 (7H, m), 7.54- 7.64 (4H, m) IR (KBr): 3246, 3031,2922, 2864, 1656, 1557, 1541 cm⁻¹ ESI-HRMS (positive ion, sodiumformate) calcd for C₂₅H₂₃N₄O ([M + H]⁺) 395.1866; found 395.1834 12.798.3  9

NMR (DMSO-d₆, δ): 2.17 (3H, s), 2.39 (3H, s), 3.60 (2H, s), 6.98 (1H,dd, J = 0.9 and 8.2 Hz), 7.27 (1H, dd, J = 1.8 and 8.2 Hz), 7.32 (1H, brs), 7.39 (1H, d, J = 8.2 Hz), 7.52 (1H, d, J = 8.2 Hz), 7.55 (1H, d, J =1.8 Hz) IR (KBr): 3050, 2922, 2865 1665, 1561 cm⁻¹ ESI-HRMS (positiveion, sodium formate) calcd for C₁₉H₁₆Cl₂N₄O ([M + H]⁺) 387.0779; found387.0748 12.7 97.8 10

NMR (DMSO-d₆, δ): 2.17 (3H, s), 2.39 (3H, s), 3.69 (2H, s), 6.99 (1H,dd, J = 0.9 and 8.2 Hz), 7.32 (1H, br s), 7.39 (1H, d, J = 8.2 Hz), 7.50(2H, d, J = 8.2 Hz), 7.64 (2H, d, J = 8.2 IR (KBr): 3268, 2923, 2865,1666, 1552 cm⁻¹ ESI-HRMS (positive ion, sodium formate) calcd forC₂₀H₁₈F₃N₄O ([M + H]⁺) 387.1433; found 387.1414 12.4 99.0 Hz) 11

NMR (DMSO-d₆, δ): 2.19 (3H, s), 2.39 (3H, s), 3.77 (2H, s), 6.98 (1H, d,J = 7.8 Hz) , 7.32 (1H, br s), 7 37- 7.50 (4H, m), 7.74 (1H, br s),7.78.7.88 (3H, m) IR (KBr): 3331, 3057, 2982, 2922, 1636, 1558 cm⁻¹ESI-HRMS (positive ion, sodium formate) calcd for C₂₃H₂₀N₄ONa ([M + H]⁺)391.1529; found 391.1516 12.2 99.0 12

NMR (DMSO-d₆, δ): 1.24 (9H, s), 2.16 (3H, s), 2.39 (3H, s), 3.54 (2H,s), 6.98 (1H, dd, J = 0.9 and 8.2 Hz), 7.17-7.21 (2H, m), 7.25-7.29 (2H,m), 7.31 IR (KBr): 3233, 3024, 2961, 2865, 1658, 1558 cm⁻¹ ESI-HRMS(positive ion, sodium formate) calcd for C₂₃H₂₅N₄O ([M + H]⁺) 375.2179;found 375.2184 13.1 98.4 (1H, br s), 7.39 (1H, d, J = 8.2 Hz) 13

NMR (DMSO-d₆, δ): 1.77 (3H, s), 2.17 (3H, s), 7.12- 7.18 (2H, m),7.50-7.65 (2H, m) IR (KBr): 3296, 3049, 2921, 2862, 1628, 1547 cm⁻¹ESI-HRMS (positive ion, sodium formate) calcd for C₁₂H₁₃N₄O ([M + H]⁺)229.1084; found 229.1091  8.5 98.3 14

NMR (DMSO-d₆, δ): 2.17 (3H, s), 3.60 (2H, s), 7.13- 7.19 (3H, m),7.24-7.30 (4H, m), 7.49-7.55(2H, m) IR (KBr): 3269, 3026, 1627, 1542cm⁻¹ ESI-HRMS (positive ion, sodium formate) calcd for C₁₈H₁₇N₄O ([M +H]⁺) 305.1397; found 305.1396 11.0 99.0 15

NMR (DMSO-d₆, δ): 2.20 (3H, s), 5.24 (1H, s), 7.14- 7.20 (2H, m),7.49-7.55 (2H, m) IR (KBr): 3310, 3043, 2905, 1626, 1559 cm⁻¹ ESI-HRMS(positive ion, sodium formate) calcd for C₁₁H₁₁N₄O ([M + H]⁺) 215.0927;found 215.0933  7.3 98.6 16

NMR (DMSO-d₆, δ): 2.19 (3H, s), 3.61 (2H, s), 7.14- 7.19 (2H, m), 7.28(1H, dd, J = 1.8 and 8.2 Hz), 7.50-7.57 (4H, m) IR (KBr): 3183, 2890,1626, 1606 cm⁻¹ ESI-HRMS (positive ion, sodium formate) calcd forC₁₈H₁₅Cl₂N₄O ([M + H]⁺) 373.0617; found 373.0621 12.6 99.1 17

NMR (DMSO-d₆, δ): 1.77 (3H, s), 2.16 (3H, s), 2.39 (3H, s), 6.98 (1H,dd, J = 0.9, 8.2 Hz), 7.32 (1H, br s), 7.40 (1H, d, J = 8.2 Hz) IR(KBr): 3308, 3018, 2920, 2861, 1635, 1573 cm⁻¹ ESI-HRMS (positive ion,sodium formate) calcd for C₁₃H₁₅N₄O ([M + H]⁺) 243.1240; found 243.1259 9.0 98.9 18

NMR (DMSO-d₆, δ): 2.39 (3H, s), 7.14-7.26 (3H, m), 7.34-7.40 (2H, m),7.54- 7.59 (2H, m), 7.63-7.67 (2H, m) IR (KBr): 3056, 2984, 1665, 1596,1514 cm⁻¹ ESI-HRMS (positive ion, sodium formate calcd for C₁₇H₁₅N₄O([M + H]⁺) 291.1240; found 291.1253 11.4 99.1 19

NMR (DMSO-d₆, δ); 2.19 (3H, s), 3.77 (2H, s), 7.13- 7.18 (2H, m),7.40-7.55 (5H m), 7.73 (1H, br s), 7.80-7.86 (3H, m) IR (KBr): 3068,2923, 1643, 1596, 1528 cm⁻¹ ESI-HRMS (positive ion, sodium formate)calcd for C₂₂H₁₈N₄O ([M + H]⁺) 355.1553; found 355.1577 12.1 99.1 20

NMR (MeOH-d₄, δ): 2.23 (3H, s), 3.39 (2H, s), 3.70 (3H, s), 7.23-7.29(2H, m), 7.51-7.56 (2H, m) IR (KBr): 2997, 2950, 1734, 1690, 1606, 1500cm⁻¹ ESI-HRMS (positive ion, sodium formate) calcd for C₁₄H₁₅N₄O₃ ([M +H]⁺) 287.1139; found 287.1145  8.7 97.5 21

NMR (DMSO-d₆, δ): 2.15 (3H, s), 3.22 (2H, m), 7.13- 7.18 (2H, m),7.49-7.55 (2H, m) IR (KBr): 3433, 2993, 1690, 1609, 1525 cm⁻¹ ESI-HRMS(positive ion, sodium formate) calcd for C₁₃H₁₃N₄O₃ ([M + H]⁺) 273.0982;found 273.0967  7.9 97.0 22

NMR (DMSO-d₆, δ): 1.78 (3H, s), 2.15 (3H, 5), 2.52 (3H, s), 6.94-6.98(1H, m), 7.05 (1H, t, J = 7.8 Hz), 7.35 (1H, d, 7.8 Hz) IR (KBr): 3243,2912, 1672, 1606, 1497 cm⁻¹ ESI-HRMS (positive ion, sodium formate)calcd for C₁₃H₁₄ N₄ONa ([M + Na]⁺) 265.1060; found 265.1062  9.2 98.3 23

NMR (DMSO-d₆, δ): 2.16 (3H, s), 3.69 (2H, s), 7.13- 7.19 (2H, m),7.20-7.29 (2H, m), 7.32-7.36 (1H, m), 7.41-7.44 (1H, m), 7.50- 7.55 (2H,m) IR (KBr): 3280, 2900, 1866, 1619, 1573 cm⁻¹ ESI HRMS (positive ion,sodium formate) calcd for C₁₆H₁₆ClN₄O ([M + H]⁺) 339.1007; found339.1022 11.8 98.5 24

NMR (DMSO-d₆, δ): 2.18 (3H, s), 3.69 (2H, s), 7.12- 7.18 (2H, m),7.47-7.54 (4H, m), 7.63 (2H, d, J = 8.2 Hz) IR (KBr): 3263, 2917, 1667,1620, 1548 cm⁻¹ ESI-HRMS (positive ion, sodium formate) calcd forC₁₉H₁₆F₃N₄O ([M + H]⁺) 373.1270; found 373.1287 12.2 98.9 25

NMR (DMSO-d₆, δ): 2.17 (3H, s), 3.59 (2H, s), 7.06- 7.11 (2H, m),7.14-7.18 (2H, m), 7.29-7.33 (2H, m), 7.51-7.54 (2H, m) IR (KBr): 3246,3069, 2910, 1657, 1605, 1507 cm⁻¹ ESI-HRMS (positive ion, sodiumformate) calcd for C₁₈H₁₅FN₄ONa ([M + Na]⁺) 345.1122; found 345.111411.2 97.5 26

NMR (DMSO-d₆, δ): 1.25 (9H, s), 2.17 (3H, s), 3.55 (2H, s), 7.13-7.22(4H, m), 7.26-7.30 (2H, m), 7.49- 7.55 (2H, m) IR (KBr): 3306, 3058,2961, 1643, 1553 cm⁻¹ ESI-HRMS (positive ion, sodium formate) calcd forC₂₂H₂₅N₄O ([M + H]⁺) 361.2022; found 361.2022 13.0 98.7 27

NMR (DMSO-d₆, δ): 2.19 (3H, s), 3.61 (2H, s), 7.13- 7.19 (2H, m),7.21-7.37 (4H, m), 7.50-7.55 (2H, m) IR (KBr): 3350, 3068, 2919, 1629,1553 cm⁻¹ ESI-HRMS (positive ion, sodium formate) calcd for C₁₈H₁₆ClN₄O([M + H]⁺) 339.1007; found 339.1006 11.8 97.9 28

NMR (DMSO-d₆, δ): 2.16 (3H, s), 3.66 (2H, s), 7.14- 7.19 (2H, m),7.34-7.37 (2H, m), 7.50-7.55 (2H, m), 7.57-7.59 (1H, m) IR (KBr): 3208,3067, 2916, 2897, 1628, 1552 cm⁻¹ ESI-HRMS (positive ion, sodiumformate) calcd for C₁₈H₁₅Cl₂N₄O ([M + H]⁺) 373.0617; found 373.0630 12.998.1 29

NMR (DMSO-d₆, δ): 2.20 (3H, s), 3.64 (2H, s), 7.12- 7.19 (2H, m),7.30-7.40 (3H, m), 7.41-7.47 (2H, m), 7.50-7.64 (6H, m) IR (KBr): 3267,3028, 1657, 1555 cm⁻¹ ESI-HRMS (positive ion, sodium formate) calcd forC₂₄H₂₂N₄O ([M + H]⁺) 381.1710; found 361.1712 12.6 98.5 30

NMR (DMSO-d₆, δ): 2.17 (3H, s), 3.59 (2H, s), 7.13- 7.19 (2H, m),7.28-7.35 (4H, m), 7.49-7.55 (2H, m) IR (KBr): 3269, 3027, 2935, 2909,1556 cm⁻¹ ESI-HRMS (positive ion, sodium formate) calcd for C₁₈H₁₇ClN₄O([M + H]⁺) 339.1007; found 339.1010 11.9 98.4 31

NMR (DMSO-d₆, δ): 2.15 (3H, s), 3.53 (2H, s), 3.70 (3H, s), 6.80-6.86(2H, m), 7.13-7.21 (4H, m), 7.50- 7.55 (2H, m) IR (KBr); 3259, 3040,2903, 2834, 1627, 1547 cm⁻¹ ESI-HRMS (positive ion, sodium formate)calcd for C₁₈H₁₈N₄O₂ ([M + H]⁺) 335.1503; found 335.1493 10.8 98.2 32

NMR (DMSO-d₆, δ): 2.16 (3H, s), 2.39 (3H, s), 3.58 (2H, s), 6.98 (1H,dd, J = 0.9 and 8.2 Hz), 7.04- 7.12 (2H, m), 7.26-7.34 (3H, m), 7.39(1H, d, J = 8.2 Hz) IR (KBr): 3177, 3040, 2920, 1887, 1601 cm⁻¹ ESI-HRMS(positive ion, sodium formate) calcd for C₁₈H₁₇FN₄O ([M + H]⁺) 337.1459;found 337.1443 11.4 98.3 33

NMR (DMSO-d₆, δ): 2.14 (3H, s), 2.40 (3H, s), 3.68 (2H, s), 6.99 (1H, d,J = 8.2 Hz), 7.19-7.36 (4H, m), 7.36-7.45 (2H, m) IR (KBr): 3191, 2924,2893, 1674, 1626, 1604 cm⁻¹ ESI-HRMS (positive ion, sodium formate)calcd for C₁₈H₁₇ClN₄O ([M + H]⁺) 353.1163; found 353.1175 12.0 98.8 34

NMR (DMSO-d₆, δ): 2.14 (3H, s), 2.39 (3H, s), 3.51 (2H, s), 3.70 (3H,s), 6.81- 6.85 (2H, m), 6.96-7.00 (1H, m), 7.16-7.21 (2H, m), 7.31(1H,br s), 7.39 (1H, d, J = 8.2 Hz) IR (KBr): 2921, 2833, 1673, 1651, 1583cm⁻¹ ESI-HRMS (positive ion, sodium formate) calcd for C₂₀H₂₀N₄O₂ ([M +H]⁺) 349.1659; found 349.1659 11.0 98.6 35

NMR (DMSO-d₆, δ): 2.18 (3H, s), 3.60 (2H, s), 7.14- 7.20 (1H, m),7.24-7.31 (4H, m), 7.46 (1H, dd, J = 1.4 and 8.2 Hz), 7.49- 7.54 (2H,m), 7.59 (1H, d, J = 8.2 Hz), 7.66-7.71 (2H, m), 7.76 (1H, br s) IR(KBr): 3308, 3028, 2915, 1855, 1555 cm⁻¹ ESI-HRMS (positive ion, sodiumformate) calcd for C₂₄H₁₈ClN₄O ([M + H]⁺) 415.1302; found 415.1327 14.297.1 36

NMR (DMSO-d₆, δ): 2.18 (3H, s), 3.60 (2H, s), 7.29- 7.35 (4H, m), 7.46(1H, dd, J = 1.4 and 8.2 Hz), 7.49-7.54 (2H, m), 7.59 (1H, d, J = 8.2Hz), 7.66- 7.71 (2H, m), 7.75 (1H, d, J = 1.4 Hz) IR (KBr): 3309, 3051,2923, 1656, 1557, 1542 cm⁻¹ ESI-HRMS (positive ion, sodium formate)calcd for C₂₄H₁₈Cl₂N₄O ([M + H]⁺) 449.0930; found 449.0925 14.9 98.9 37

NMR (DMSO-d₆, δ): 2.18 (3H, s), 3.61 (2H, s), 7.14- 7.20 (1H, m),7.24-7.36 (5H, m), 7.43-7.50 (3H, m), 7.59 (1H, d, J = 8.2 Hz),7.64-7.66 (2H, m), 7.76 (1H, br s) IR (KBr): 3338, 3025, 2897, 1623,1577, 1541 cm⁻¹ ESI-HRMS (positive ion, sodium formate) calcd forC₂₄H₂₁N₄O ([M + H]⁺) 381.1710; found 381.1716 13.2 98.4 38

NMR (DMSO-d₆, δ): 2.18 (3H, s), 3.60 (2H, s), 7.29- 7.37 (5H, m),7.44-7.50 (3H, m), 7.59 (1H, d, J = 8.2 Hz), 7.64-7.68 (2H, m), 7.76(1H, br s) IR (KBr): 3344, 3028, 2903, 1624, 1577 cm⁻¹ ESI-HRMS(positive ion, sodium formate) calcd for C₂₄H₂₈ClN₄O ([M + H]⁺)415.1320; found 415.1323 13.9 97.7 39

NMR (DMSO-d₆, δ): 1.78 (3H, s), 2.18 (3H, s), 2.35 (3H, s), 7.27 (2H, d,J = 7.8 Hz), 7.42 (1H, dd, J = 1.8, 8.2 Hz), 7.51-7.59 (3H, m), 7.73(1H, br s) IR (KBr): 3291, 3023, 2923, 2861, 1633, 1569 cm⁻¹ ESI-HRMS(positive ion, sodium formate) calcd for C₁₈H₁₈N₄O ([M + H]⁺) 319.1553;found 319.1552 11.6 97.0 40

NMR (DMSO-d₆, δ): 2.17 (3H, s), 2.35 (3H, s), 3.60 (2H, s), 7.13-7.21(1H, m), 7.23-7.31 (6H, m), 7.43 (1H, dd, J = 1.8, 8.2 Hz), 7.51-7.59(3H, m), 7.72 (1H, br s) IR (KBr): 3446, 3027, 2962, 2873, 1632, 1556cm⁻¹ ESI-HRMS (positive ion, sodium formate) calcd for C₂₅H₂₃N₄O ([M +H]⁺) 395.1866; found 395.1852 13.6 98.0 41

NMR (DMSO-d₆, δ): 2.17 (3H, s), 2.34 (3H, s), 3.59 (2H, s), 7.24-7.36(6H, m), 7.43 (1H, dd, J = 1.8 and 8.2 Hz), 7.52-7.59 (3H, m), 7.72 (1H,br s) IR (KBr): 3253, 3028, 2921, 2894; 1655, 1557 cm⁻¹ ESI-HRMS(negative ion, sodium formate) calcd for C₂₅H₂₀ClN₄O ([M + H]⁺)427.1331; found 427.1326 14.4 96.5 42

NMR (DMSO-d₆, δ): 2.39 (3H, s), 2.41 (3H, s), 7.07 (1H, dd, J = 0.9 and8.2 Hz), 7.12-7.17 (1H, m), 7.32-7.38 (3H, m), 7.44 (1H, d, J = 8.2 Hz),7.64- 7.69 (2H, m) IR (KBr): 3060, 1660, 1596, 1514 cm⁻¹ ESI-HRMS(positive ion, sodium formate) calcd for C₁₈H₁₇N₄O ([M + H]⁺) 305.1397;found 305.1402 11.8 98.6 43

NMR (DMSO-d₆, δ): 2.08 (3H, s), 5.28 (1H, s), 7.13- 7.24 (4H, m),7.26-7.33 (8H, m), 7.48-7.53 (2H, m) IR (KBr): 3229, 3025, 1656, 1559cm⁻¹ ESI-HRMS (positive ion, sodium formate) calcd for C₂₄H₂₁N₄N ([M +H]⁺) 381.1710; found 381.1707 13.0 98.0 44

NMR (DMSO-d₆, δ): 2.17 (3H, s), 3.59 (2H, s), 7.18 (1H, dd, J = 1.8 and8.2 Hz), 7.28-7.35 (4H, m), 7.51 (1H, d, J = 8.2 Hz), 7.55 (1H, d, J =1.8 Hz) IR (KBr): 3294, 3077, 1630, 1568, 1536 cm⁻¹ ESI-HRMS (positiveion, sodium formate) calcd for C₁₈H₁₅Cl₂N₄O ([M + H]⁺) 373.0617; found373.0600 13.9 98.7 45

NMR (DMSO-d₆, δ): 0.81- 0.90 (3H, m), 1.21-1.34 (6H, m), 1.40-1.52 (2H,m), 2.16 (3H, s), 2.22 (2H, t, J = 7.3 Hz), 2.39 (3H, s), 6.97 (1H, dd,J = 0.9, 8.2 Hz), 7.31 (1H, br s), IR (KBr): 3169, 3022, 2928, 2855,1660, 1552 cm⁻¹ ESI-HRMS (positive ion, sodium formate) calcd forC₁₈H₂₅N₄O ([M + H]⁺) 313.2022; found 313.2046 12.2 98.3 7.39 (1H, d, J =8.2 Hz) 46

NMR (DMSO-d₆, δ): 0.86- 1.00 (2H, m), 1.08-1.24 (3H, m), 1.40-1.71 (6H,m), 2.11 (2H, d, J = 6.9 Hz), 2.15 (3H, s), 2.39 (3H, s), 6.97 (1H, dd,J = IR (KBr); 3093, 2919, 2849, 1675, 1589, 1552 cm⁻¹ ESI-HRMS (positiveion, sodium formate) calcd for C₁₈H₂₅N₄O ([M + H]⁺) 325.2823; found325.2030 12.3 99.0 0.9, 8.2 Hz), 7.31 (1H, br s), 7.38 (1H, d, J = 8.2Hz) 47

NMR (CDCl₃, δ): 1.93 (3H, s), 2.22 (3H, s), 4.24 (3H, s), 7.28-7.36 (3H,m), 7.56-7.61 (1H, m) IR (KBr): 3431, 3058, 2922, 2861, 1665, 1561, 1511cm⁻¹ ESI-HRMS (positive ion, sodium formate) calcd for C₁₃H₁₅N₄O ([M +H]⁺) 243.1240; found 243.1248  8.7 98.6 48

NMR (DMSO-d₆, δ): 5.94 (1H, s), 7.22-7.28 (2H, m), 7.39-7.51(3H, m),7.55- 7.61 (2H, m), 7.88-7.92 (2H, m) IR (KBr): 3334, 3068, 1678; 1631,1600, 1555 cm⁻¹ ESI-HRMS (positive ion, sodium formate) calcd forC₁₆H₁₃N₄O ([M + H]⁺) 277.1084; found 277.1093 19.0 98.7

Furthermore, using the corresponding starting compounds and in the samemanner as in Example 1, the compounds of Examples 49-57 weresynthesized. The following Tables summarize the structures of Examples49-57 and physicochemical properties thereof.

TABLE 2 HPLC reten- tion Ex. time purity No 1H-NMR IR ESI-HRMS (min) (%)49

NMR (DMSO-d₆, δ): 2.06 (3H, s), 7.18-7.24 (2H, m), 7.46-7.60 (5H, m),7.73-7.78 (2H, m) IR (KBr): 3173, 1665, 1640, 1662 cm⁻¹ ESI-HRMS(positive ion, sodium formate) calcd for C₁₇H₁₅N₄O ([M + H]⁺) 291.1240;found 291.1236 11.1 98.1 50

NMR (DMSO-d₆, δ): 3.84 (2H, s), 7.13-7.29 (7H, m), 7.41-7.49 (3H, m),7.55-7.66 (4H, m) IR (KBr): 3186, 3061, 1665, 1633, 1591, 1559 cm⁻¹ESI-HRMS (positive ion, sodium formate) calcd for C₂₃H₁₉N₄O ([M + H]⁺)367.1663; found 367.1567 13.2 97.8 51

NMR (DMSO-d₆, δ): 2.14 (3H, s), 2.38 (3H, s), 3.21 (2H, s), 6.98 (1H, d,J = 7.5 Hz), 7.31 (1H, s), 7.39 (1H, d, J = 7.5 Hz) IR (KBr): 3175,3034, 1679, 1651, 1635, 1605, 1559, 1507 cm⁻¹ ESI-HRMS (negative ion,sodium formate) calcd for C₁₄H₁₃N₄O₃ ([M − H]⁻) 285.0993; found 285.098352

NMR (DMSO-d₆, δ): 7.14 (1H, t, J = 7.3 Hz), 7.20- 7.30 (3H, m), 7.33(2H, d, J =7.3 Hz), 7.37-7.45 (3H, m), 7.45-7.55 (2H, m), 7.58 (1H, d, J= 8.7 Hz), 7.62 (1H, br s) IR (KBr); 3101, 3073, 3059, 1651, 1596, 1572,1555, 1510, 1466 cm⁻¹ ESI-HRMS (negative ion, sodium formate) calcd forC₂₂H₁₄ClN₄O ([M − H]⁻) 385.0856; found 385.0870 53

NMR (CDCl₃, δ): 2.00 (3H, s), 2.44 (3H, br s), 7.06 (1H, br s), 7.15-7.50 (7H, m), 8.43 (2H, br s) IR (KBr): 3173, 3026, 2923, 1662, 1652,1634, 1617, 1558, 1508, 1473 cm⁻¹ ESI-HRMS (negative ion, sodiumformate) calcd for C₁₈H₁₅N₄O ([M − H]⁻) 303.1246; found 303.1269 54

NMR (DMSO-d₆, δ): 2.17 (3H, s), 3.61 (2H, s), 7.13- 7.22 (1H, m),7.23-7.30 (4H, m), 7.32 (1H, dd, J = 8.2 and 1.8 Hz), 7.49 (1H, d, J =8.2 Hz), 7.70 (1H, d, J = 1.8 Hz) IR (KBr): 3030, 2923, 2850, 1706,1637, 1592, 1576, 1545, 1509 cm⁻¹ ESI-HRMS (negative ion, sodiumformate) calcd for C₁₈H₁₄BrN₄O ([M − H]⁻) 381.0345; found 381.0348 55

NMR (CDCl₃, δ): 2.39 (3H, s), 7.04 (2H, d, J = 7.8 Hz), 7.05-7.50 (12H,m) IR (KBr): 3419, 3059, 2974, 1641, 1615, 1600, 1565, 1513, 1469 cm⁻¹ESI-HRMS (negative ion, sodium formate) calcd for C₂₃H₁₇N₄O ([M − H]⁻)366.1402; found 365.1416 56

NMR (CDCl₃, δ): 1.25 (3H, t, J = 7.3 Hz), 2.24 (3H, s), 2.44 (3H, s),2.60-2.70 (4H, m), 4.12 (2H, q, J = 7.3 Hz), 7.05 (1H, d, J = 7.8 Hz),7.23 (1H, s), 7.30 (1H, d, J = IR (KBr): 3206, 2978, 1732, 1654, 1559,1489 cm⁻¹ ESI-HRMS (negative ion, sodium formate) calcd for C₁₇H₁₉N₄O₃([M − H]⁻) 327.1457; found 327.1349 7.8 Hz), 57

NMR (DMSO-d₆, δ): 2.17 (3H, s), 2.36-2.55 (7H, m), 6.98 (1H, d, J = 7.8Hz), 7.3 (1H, s), 7.39 (1H, d, J = 7.8 Hz) IR (KBr): 3267, 2957, 1684,1654, 1637, 1595, 1559, 1489 cm⁻¹ ESI-HRMS (negative ion, sodiumformate) calcd for C₁₅H₁₅N₄O₃ ([M − H]⁻) 299.1139; found 299.1121

Experimental Example 1 Method for Evaluation of PCA-1 InhibitoryActivity

To an enzyme reaction solution (50 mM trishydrochloric acid buffer (pH8.0), 2 mM ascorbic acid, 100 μM oxoglutaric acid, 40 μM ferric sulfate)containing 80 fmol 3-methyl cytosine-containing oligo DNA as a substratewere added a test compound (10 μM, 1 μM) and 4 ng silkworm recombinantPCA-1, and the mixture was incubated at 37° C. for 1 hr. Aftercompletion of the reaction, the enzyme reaction solution was 20-folddiluted with water to quench the reaction. Using 2 μL thereof, real-timePCR (Bio-Rad iQ SYBR Green Supermix) was performed in a 20 μL reactionsystem. The analytical curve was formed using a dilution series of thenon-methylated oligoDNA. The primers used were forward primer 24 basesand reverse primer 22 bases. Reaction conditions: 95° C., 10 seconds→40cycles of 95° C., 5 seconds, 61° C., 30 seconds, and 72° C., 15seconds→95° C., 1 min→55° C., 1 min→55° C., 10 seconds, after whichincreased by 0.5° C. to 95° C. for 10 seconds→preserved at 25° C.

The degree of demethylation in the presence or absence of the testcompound was compared and the inhibitory activity was evaluated.

The PCA-1 inhibitory activity of the compound of the present inventionis shown in Table 3.

TABLE 3 Example PCA-1 inhibitory activity (%) No. 10 μM 1 μM 1 81 24 360 21 4 82 50 5 91 50 11 82 36 13 76 19 14 80 35 15 76 −1 17 76 25 18 7427 19 76 38 24 67 61 25 68 39 31 85 47 32 81 49 33 82 54 34 80 49 35 7725 37 64 38 40 61 21 42 65 37 43 73 50 45 81 43 46 81 47

Example Nos. 52-54, 56 and 57 also confirmed good PCA-1 inhibitoryactivity.

Experimental Example 2 Evaluation of Cancer Cell ProliferationSuppressive Action

cell line used: DU145 (prostate cancer cell: Institute of Development,Aging and Cancer, Tohoku University, Cell Resource Center for BiomedicalResearch)

evaluation of scaffolding dependency growth suppressive action:

The cells were plated on a 96 well plate at 5×10³ cells/well/90 μL, andcultured overnight. The test compound (10 μM) was added and, afterculture for 48 hr, a 1:9 mixture of aqueous1-methoxy-5-methylphenazinium methylsulfate (PMS) solution and2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium,monosodium salt (WST-1)/20 mM4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) solution(DOJIN) was added by 10 μL, and the absorbance was measured at 450 nm 2hr later. As a control wavelength, 630 nm was used.

The cancer cell proliferation inhibitory activity of the compound of thepresent invention is shown in Table 4.

TABLE 4 Example DU145 proliferation No. inhibitory activity (%) 1 60 1322 14 45

Furthermore, the compound of the present invention also showed a cancercell proliferation inhibitory activity against PC3 (other prostatecancer cell), and Mia-Paca2 and Panc-1 (pancreatic cancer cells).

Experimental Example 3 Evaluation of Antitumor Action Using ProstateCancer Xenograft Model

A prostate cancer xenograft model was produced as shown below.

DU145 cells (4×10⁶ cells) were mixed with BD Matrigel Basememt MembraneMatrix High Concentration (Becton, Dickinson and Company), andsubcutaneously transplanted to the back of BALB/c nu/nu mouse. Aftertransplantation, the tumor was isolated when it reached a volume ofabout 200 mm³, and subcutaneously transplanted into the back of adifferent BALB/c nu/nu mouse. This operation was repeated three times togenerate a tumor derived from DU145 cells that grow stably. A modelmouse for the evaluation of the compound was prepared by finely cuttingthe in vivo passaged tumor into about 10 mm³, and subcutaneouslytransplanting same into the back of a BALB/c nu/nu mouse.

The compound of Example 1 was suspended in 0.5 w/v % sterilecarboxycellulose (Wako Pure Chemical Industries, Ltd.), andsubcutaneously administered to the back. The volume of the tumor wascalculated using the formula of (long diameter)×(short diameter)²×0.5.The rate of changes in the tumor volume and body weight was evaluatedand the results are shown in FIG. 1.

Industrial Applicability

The compound of the present invention has a superior action to inhibitthe PCA-1 enzyme activity, and is useful for the prophylaxis and/ortreatment of a disease involving PCA-1. Particularly, the compound ofthe present invention is useful as an anti-cancer agent against prostatecancer, pancreatic cancer, non-small cell lung cancer and the like.

This application is based on patent application No. 2012-045267 (filingdate: Mar. 1, 2012) filed in Japan, the contents of which areencompassed in full herein.

The invention claimed is:
 1. A compound represented by the formula (I):

wherein R₁ is a C₁₋₆ alkyl group optionally substituted by a halogenatom, a C₆₋₁₀ aryl group optionally substituted by one or moresubstituents selected from the group consisting of a halogen atom and aC₁₋₆ alkyl group, or a halogen atom; R₂ is a C₁₋₆ alkyl group or a C₆₋₁₀aryl group; R₃ is a C₇₋₁₁ aralkyl group optionally substituted by one ormore substituents selected from the group consisting of a halogen atom,a C₁₋₆ alkyl group optionally substituted by a halogen atom, a C₆₋₁₀aryl group and a C₁₋₆ alkoxy group, a C₆₋₁₀ aryl group, or a C₁₋₆ alkylgroup optionally substituted by one or more substituents selected fromthe group consisting of a C₆₋₁₀ aryl group, a C₁₋₆ alkoxy-carbonylgroup, a carboxyl group, and a C₃₋₆ cycloalkyl group; and R₄ is ahydrogen atom; or a pharmaceutically acceptable salt thereof.
 2. Thecompound according to claim 1 which is represented by the followingformula:

or a pharmaceutically acceptable salt thereof.
 3. A pharmaceuticalcomposition comprising the compound according to claim 1 or apharmaceutically acceptable salt thereof and a pharmaceuticallyacceptable carrier.
 4. The pharmaceutical composition according to claim3, wherein the compound is a compound represented by the followingformula:

or a pharmaceutically acceptable salt thereof.